JP5563010B2 - Wings, airflow generators, heat exchangers, micromachines and gas treatment equipment - Google Patents

Description

  The present invention relates to a blade, an air flow generation device, a heat exchange device, a micromachine, and a gas processing device that generate an air flow by the action of discharge plasma.

  The phenomenon in which airflow is induced by the action of discharge plasma generated between opposing metal electrodes is called ion wind, and its principle and application have been studied in the field of electrostatic precipitators (for example, non-winding). (See Patent Document 1). However, conventionally used ion wind generating methods use a metal needle electrode or a metal linear electrode for the metal flat plate electrode, and the discharge becomes unstable depending on the environment in which the discharge is generated. For example, in high-temperature gas or dust-containing gas, there is a risk that the discharge will be transferred to the arc and excessive power is applied, the airflow induction efficiency is reduced, and there is a risk of damage to the equipment due to heat generation. When this occurs, it is necessary to stop the application of voltage. Therefore, the effect of ionic wind is limited, and its application is not widespread.

  On the other hand, for example, as a method of controlling aerodynamic characteristics on the surface of an object such as a wing, so far, the wing shape has been optimized to suppress separation of the wing surface flow under the operating air conditions. Has been approached.

Journal of the Institute of Electrical Engineers of Japan, Vol. 97, No. 5 (1977), p259-p266

  The structural optimization of a wing related to aerodynamic characteristics such as, for example, a conventional wing described above can optimize the characteristics in a specific range of air conditions, but the temperature and the air volume change in a wide range, for example. In some cases, it was impossible to optimize the characteristics corresponding to the range. Attempts have also been made to expand the range of optimization by the mechanical drive unit, but it has been impossible to follow a rapid fluctuation below the control time constant of the drive unit.

  On the other hand, if the air flow like the ionic wind described above can be generated in a minute space, the air flow in the immediate vicinity of the object surface can be changed, and control of aerodynamic characteristics with a wide control range and a very short control time constant. It can be used as a means. In addition to blades, the present invention can also be used as an aerodynamic characteristic control means, an airflow generation means, or the like in a device that performs a predetermined function using a fluid flow.

  Therefore, the present invention has been made to solve the above-described problems, and can generate airflow stably even under high temperature and dusty environment due to airflow induction phenomenon caused by discharge plasma, and has aerodynamic characteristics. It is an object of the present invention to provide a blade, an airflow generation device, a heat exchange device, a micromachine, and a gas processing device capable of controlling the above.

  In order to achieve the above object, the wing of the present invention generates an air flow by applying a voltage between the first electrode and the second electrode disposed via a solid dielectric and discharging it. An airflow generating unit is provided at a predetermined position on the blade surface to generate lift.

The dielectric is constituted by a block-shaped dielectric block, and the first electrode is provided to be exposed from one surface of the dielectric block, or embedded in the dielectric block, and The second electrode is shifted from the first electrode in a direction horizontal to the surface of the dielectric block and is separated from the first electrode and embedded in the dielectric block, and the relative permittivity of the dielectric block The ratio (ε / t) between ε and the thickness t (mm) of the dielectric block perpendicular to the direction in which the airflow is generated is 20 / mm or less .

It is the perspective view which showed typically the airflow generator of 1st Embodiment. It is a schematic cross section for demonstrating the mode of discharge when a positive voltage is applied to the electrode shown in FIG. It is the perspective view which showed typically the airflow generator of 2nd Embodiment. It is AA sectional drawing of FIG. It is the perspective view which showed typically the wing | blade provided with the airflow generator on the wing | blade upper surface side. It is the figure which showed typically the cross section of the wing | blade in order to demonstrate the flow of the airflow on a wing | blade upper surface. It is the figure which showed typically the cross section of the wing | blade in order to demonstrate the flow of the airflow on a wing | blade upper surface. It is the figure which showed typically the cross section of the wing | blade in order to demonstrate the flow of the airflow on a wing | blade upper surface. It is the figure which showed typically the cross section of a part of moving body provided with the airflow generator on the front side surface. It is the perspective view which showed typically the heat exchange apparatus provided with the airflow generator on the heat-transfer surface. It is the perspective view which showed typically the micromachine provided with the airflow generator on the side surface and the upper surface. It is the perspective view which showed typically the active species production | generation part of the gas processing apparatus provided with the airflow generator. It is the top view which showed typically the airflow generator for observing the form of discharge when changing pressure conditions. It is a figure which shows the form of the discharge when a pressure condition is changed. It is a figure which shows the form of the discharge when a pressure condition is changed. It is a figure which shows the spark voltage in each gas kind. It is sectional drawing which showed the airflow generator typically. It is a figure which shows the result of having observed the flow velocity distribution of the height direction of the uniform flow by the smoke wire method. It is a figure which shows the result of having observed the flow velocity distribution of the height direction of the airflow which generate | occur | produced with the airflow generator in the uniform flow by the smoke wire method. It is sectional drawing which showed the airflow generator typically. It is a figure which shows the velocity distribution of the airflow which generate | occur | produced with the airflow generator. It is sectional drawing for demonstrating the phenomenon of the peeling of the flow on a blade surface. It is a figure which shows the result of having measured the blade surface pressure in the predetermined position on a blade surface. It is a figure which shows the maximum value of speed distribution when a voltage peak value is made constant and a voltage frequency is changed. It is a figure which shows the maximum value of speed distribution when changing the rise time ratio when making a voltage peak value and a voltage frequency constant. It is a figure which shows the maximum value of speed distribution when a voltage peak value, a voltage frequency, and a voltage waveform are made constant and a voltage is applied intermittently and a duty ratio is changed. It is a figure which shows the electric current voltage waveform of discharge when the high voltage power supply which has a transformer is used for the airflow generator which concerns on this invention. It is a figure which shows the relationship between ratio L1 / t3 of electrode width L1 and dielectric thickness t3, and energy conversion efficiency. It is a figure which shows the relationship between ratio (epsilon) / t3 of the dielectric constant (epsilon) and the thickness t3 of the dielectric material 20, and energy conversion efficiency.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view schematically showing an airflow generation device 10 according to the first embodiment.

  As shown in FIG. 1, the airflow generation device 10 applies a voltage between a dielectric 20, a pair of electrodes 21, 22 opposed to each other via the dielectric 20, and the electrodes 21, 22 via a cable 23. It is mainly composed of a discharge power supply 24 to be applied.

  The dielectric 20 is made of a known solid dielectric material. Specifically, the material constituting the dielectric 20 is an electrically insulating material such as an inorganic insulator such as alumina, glass or mica, or an organic insulator such as polyimide, glass epoxy, rubber or Teflon (registered trademark). Although it is mentioned, it is not restricted to these, It selects suitably from a well-known solid dielectric material in the environment where the airflow generator 10 is used. Note that at least the surface of the dielectric 20 on the electrode 21 side is preferably flat.

Here, when the thickness of the dielectric 20 is t and the relative dielectric constant is ε, ε / t is preferably 20 / mm or less. The reason why it is preferable to set ε / t within this range will be described later.

  The electrode 21 is composed of a rod-shaped electrode, and the electrode 22 is composed of a flat electrode. The electrode 21 is provided on the surface of the dielectric 20, and the electrode 22 is provided on the back surface of the dielectric 20 that is shifted in the direction in which an air flow is generated from the electrode 21. Here, the electrode 21 may be disposed at a predetermined interval from the surface of the dielectric 20 or may be embedded in the dielectric 20. In addition, the electrode 22 may be disposed at a predetermined interval from the back surface of the dielectric 20 or may be embedded in the dielectric 20. In addition, when embedding the electrode 21 and the electrode 22 in the dielectric material 20, each electrode is arrange | positioned through the dielectric material 20, without contacting directly. Further, when the electrode 21 and / or the electrode 22 is embedded in the dielectric 20, it is preferably embedded in parallel to the surface (plane) of the dielectric 20. These electrodes are made of a known conductive material, and materials constituting the electrodes 21 and 22 are appropriately selected from known conductive materials according to the environment in which the airflow generation device 10 is used. Electrons and ions (positive ions and negative ions) are generated by performing a dielectric barrier discharge between these electrodes via the dielectric 20.

  Here, the diameter when the electrode 21 is formed into a rod shape, or the width when the electrode 21 is formed into a flat plate shape (the length in the direction in which the airflow is generated) is 20 t or less when the thickness of the dielectric 20 is t. It is preferable that it is 2t or less. On the other hand, when the electrode 22 is formed in a flat plate shape, the width is preferably at least three times the dielectric breakdown distance of the gas parallel plate at the voltage, pressure, and temperature. The reason why the widths of the electrodes 21 and 22 are preferably set in the above-described range will be described later.

  The discharge power supply 24 functions as a voltage application mechanism and applies a voltage between the electrodes 21 and 22. The output voltage from the discharge power supply 24 is, for example, an output voltage having a pulse-like waveform (positive polarity, negative polarity, both positive and negative polarities (alternating voltage)) or an alternating waveform (sine wave, intermittent sine wave). .

  As the discharge power source 24, for example, a high voltage power source having a transformer as described in Japanese Patent Application Laid-Open No. 2004-278369 is used, and the leakage inductance of the transformer from the transformer primary winding and the discharge part (interelectrode part). It is preferable to use a method in which a resonance voltage is applied to the discharge part by applying a step voltage to a resonance circuit formed including the capacitance of According to this method, the transformer can be reduced in size as compared with a method in which a sinusoidal AC voltage is applied to the primary side of the transformer. In particular, it is preferable to use such a power source when it is desired to reduce the size and cost of the power source.

  Next, the operation of the airflow generation device 10 will be described.

  When a voltage is applied between the electrodes 21 and 22 from the discharge power supply 24 and a potential difference equals or exceeds a certain threshold value, a discharge occurs between the electrodes 21 and 22, and discharge plasma is generated along with the discharge. Here, since the dielectric 20 is interposed between the electrodes 21 and 22, arc discharge is not caused even at high temperature or in a dust-containing environment, and dielectric barrier discharge that can be stably maintained occurs. Further, the dielectric barrier discharge is a creeping discharge formed along the dielectric 20. This dielectric barrier discharge can generate an air flow 35 in a predetermined direction.

  Hereinafter, the formation process of the dielectric barrier discharge under the atmospheric pressure and the principle of the air flow generation associated therewith will be described with reference to FIG. 1 and FIG. FIG. 2 is a schematic cross-sectional view for explaining the state of discharge when a positive voltage is applied to the electrode 21 shown in FIG.

  A dielectric barrier discharge under atmospheric pressure generally forms a discharge column called a myriad of streamers. The principle of airflow generation is considered to be a phenomenon that occurs as a result of the momentum of electrons and ions being transferred to neutral gas molecules during the streamer process.

  When a high voltage is applied between the electrodes 21 and 22, electrons that are treated between the electrodes 21 and 22 or electrons accidentally ionized by cosmic rays or the like become seeds and cause ionization and proliferation in an electric field. This ionization growth produces positive ions and electrons. When the positive ions have a sufficiently high density, they form a streamer 30 for the cathode toward the cathode by the action of space charge. Further, when the density becomes sufficiently high, the electrons form an anode-oriented streamer 31 toward the anode.

The force F applied to neutral particles of electrons and ions has the relationship of the following formula (1).
F ∝ (n ⁺ −n ⁻ ) × E (1)
Here, n ⁺ is the density of positive ions, and n ⁻ is the density of electrons or negative ions.

As shown in the equation (1), in the plasma portion where positive ions and electrons are locally mixed at the same density, “n ⁺ = n ⁻ ” is obtained, and the force F is canceled and can be regarded as “0”. In the progress of the streamer, the region where “n ⁺ ≠ n ⁻ ” is only the streamer tip portion, and it is considered that the force F acts only on this portion. There are many positive ions at the tip of the cathode streamer 30 and many electrons or negative ions at the tip of the anode streamer 31. Therefore, a force in the direction of the electric field is induced at the tip of the cathode streamer 30, and a force in the direction opposite to the electric field is induced at the tip of the anode streamer 31.

  In the case of the electrode configuration described above, since the electric field strength in the vicinity of the electrode 21 is increased, the start point of the streamer is considered to be in the vicinity of the electrode 21 (point P) (see FIG. 2). When a positive voltage is applied to the electrode 21, the electric field is directed from the electrode 21 to the electrode 22, and thus the cathode streamer 30 travels toward the electrode 22 across the space. At this time, the positive ions impart momentum to the neutral particles. On the other hand, the streamer 31 for the anode advances toward the electrode 21, contrary to the streamer 30 for the cathode, but the distance from the point P to the electrode 21 is short and the development time is also short. Therefore, when the forces from both streamers are averaged, the direction is from the electrode 21 toward the electrode 22, and an air flow 35 is generated in that direction.

  Next, when a negative voltage is applied to the electrode 21, the direction of the electric field is reversed from that in the above case, and therefore the cathode streamer advances a short distance from the point P to the electrode 21 in a short time. On the other hand, the streamer for anode goes to the electrode 22 across a long space from the point P to the electrode 22. Therefore, as in the case where a positive voltage is applied to the electrode 21, the average force from both streamers is directed from the electrode 21 to the electrode 22, and an air flow 35 is generated in that direction. Since the generation probability of the streamer for the anode is lower than that of the streamer for the cathode, the speed of the generated air flow 35 is smaller than that when a positive voltage is applied to the electrode 21.

  Here, the force F applied to the neutral particles of electrons and ions changes depending on the voltage applied between the electrodes 21 and 22, and the speed of the air flow 35 generated thereby also changes. That is, by adjusting the voltage applied between the electrodes 21 and 22, the speed of the generated air flow 35 can be adjusted. As a method for adjusting the voltage, a conventionally known method, for example, a method of adjusting a voltage peak value, a voltage frequency, a voltage waveform, a duty ratio, or the like can be applied. It is possible to appropriately select an optimum voltage adjustment method according to the structure of the airflow generation device and the target of airflow control.

  Next, the progress process of the streamer will be described with reference to FIG.

  The streamer 30 starting from the point P has a form of a discharge column having a strong space charge at the tip and a plasma with a high degree of ionization in the back, and crosses the space while ionizing the space by the space electric field at the tip. It progresses and reaches the dielectric surface. Charges that are transported and stored on the dielectric surface charge the surface and relax local electric fields. Therefore, the streamer further advances away from the point P toward the dielectric surface where no charge is accumulated, and charges the dielectric surface of that portion. In this way, the streamer grows while sequentially charging the dielectric surface. However, since the plasma that has been pulled backward has a finite resistivity, when the streamer reaches a predetermined length, the electric field at the streamer tip decreases due to a voltage drop due to the resistivity, and ionization due to the spatial electric field at the tip. Stops. At this point, the streamer stops growing, leaving a charged surface charge on the dielectric surface along the propagation path.

  As described above, when a DC voltage is applied between the electrodes 21 and 22 in the dielectric barrier discharge under atmospheric pressure, electric charges accumulate on the dielectric surface as the streamer discharge progresses, and the electric field between the electrodes 21 and 22 is relaxed. Eventually, the electric field cannot maintain the ionization of the space, and the discharge stops. In order to prevent the discharge from being stopped, it is necessary to remove the electric charge stored on the dielectric surface. For this purpose, there is an alternating alternating current that is a pulsed positive / negative bipolar voltage between the electrodes 21 and 22. It is preferable to apply a voltage or an alternating voltage. Thus, by applying an alternating voltage or an alternating voltage between the electrodes 21 and 22, it becomes possible to perform a dielectric barrier discharge continuously.

The amount of charge transported by one streamer from the start of streamer discharge to the stop of discharge due to charge accumulation on the dielectric surface is proportional to the capacitance of the dielectric involved in the streamer discharge. When the capacitance is large, a large amount of charge is transported in one discharge. However, when the amount of charge is too large, the gas is heated by the current caused by the large amount of charge. When the gas is heated, the proportion of the discharge input that shifts to thermal energy increases, and the discharge input cannot be effectively transferred to kinetic energy. That is, as the capacitance increases, the energy conversion efficiency for shifting to kinetic energy deteriorates. Since the capacitance is a value proportional to ε / t using the relative permittivity ε and thickness t of the dielectric, the energy conversion efficiency that shifts to kinetic energy deteriorates as ε / t increases. Become. Therefore, ε / t is preferably 20 / mm or less at which the energy conversion efficiency for shifting to kinetic energy increases remarkably.

  Further, when the streamer reaches the end of the electrode 22 in the process of moving away from the point P, the external electric field rapidly decreases thereafter, so that the discharge cannot be maintained and the streamer stops. Therefore, the width of the electrode 22 is preferably sufficiently longer than the distance at which the streamer self-stops due to its resistivity. The width of the electrode 22 is preferably at least three times the dielectric breakdown distance of the gas parallel plate at least at the voltage, pressure, and temperature.

  In addition, the electric field strength at the point P where streamer progress starts increases as the diameter of the electrode 21 decreases, and discharge can be generated at a lower voltage. When the diameter of the electrode 21 is increased, the electric field strength is weakened and the energy conversion efficiency is lowered. Therefore, the ratio L1 between the diameter L1 when the electrode 21 is formed of a rod or the width L1 of the flat plate when the electrode 21 is formed of a flat plate (the length in the direction in which airflow is generated) L1 and the thickness t of the dielectric. / T is preferably 2 or less at which the energy conversion efficiency increases remarkably. However, if L1 / t is 20 or less in the experiments so far, a sufficient wind speed is observed. Therefore, if L1 / t is 20 or less, it can be applied to various applications described in the present invention. is there.

  Here, the electrode 21 and the electrode 22 are each configured to have a plane-symmetric shape, and the dielectric 20 is disposed on a plane of symmetry, that is, a plane located at an equal distance from each electrode, and an alternating voltage is applied between the electrodes 21 and 22. Is applied, the speed of the airflow induced when a positive voltage is applied to the electrode 21 is the same as the speed of the airflow induced when a negative voltage is applied to the electrode 22. For this reason, airflows having opposite directions and the same speed are alternately induced to generate airflows that vibrate at the same period as the voltage period. Therefore, in the case of generating an airflow in one direction, when the electrode 21 and the electrode 22 are configured in plane symmetry, the dielectric 20 is disposed so that the dielectric 20 is not positioned on the plane of symmetry, that is, It is preferable to dispose the dielectric 20 so as to be shifted from the symmetry plane to either one of the electrodes.

  On the other hand, when the electrode 21 and the electrode 22 are configured to be asymmetrical, that is, the electrode 21 and the electrode 22 are not configured to be plane-symmetric, and an alternating voltage is applied between the electrodes 21 and 22, When a voltage is applied and when a negative voltage is applied to the electrode 21, airflows having the same direction and different speeds are induced. When this airflow is time-averaged, an airflow in a certain direction is obtained. In particular, as shown in FIG. 1, when the electrode area of the electrode 21 facing the electrode 22 is made smaller than the area of the electrode 22, an air flow is generated in the direction from the electrode 21 toward the electrode 22 as described above.

  As described above, according to the airflow generation device 10 of the first embodiment, a voltage is applied between the pair of electrodes 21 and 22 that are arranged to face each other via the dielectric 20 to generate a dielectric barrier discharge. As a result, an air flow can be generated in a predetermined direction. Also, when it is desired to generate an air flow in a certain direction, and the electrode 21 and the electrode 22 are each configured to have a plane symmetrical shape, is the dielectric 20 disposed so that the dielectric 20 is not located on the plane of symmetry? Alternatively, it is effective to configure the electrode 21 and the electrode 22 in non-target shapes. Further, the speed of the generated air flow 35 can be adjusted by the voltage applied between the electrodes 21 and 22.

(Second Embodiment)
FIG. 3 is a perspective view schematically showing the airflow generation device 40 of the second embodiment. 4 is a cross-sectional view taken along the line AA in FIG. In addition, the same code | symbol is attached | subjected to the structure same as the airflow generator 10 of 1st Embodiment, and the overlapping description is abbreviate | omitted or simplified.

  As shown in FIG. 3 and FIG. 4, the airflow generation device 40 includes an electrode 42 that is exposed on the same plane as the surface of the dielectric 41, a distance from the surface of the electrode 42 and the dielectric 41, and a dielectric It is mainly composed of an electrode 43 that is spaced apart from the surface of the body 41 in the horizontal direction and embedded in the dielectric 41, and a discharge power source 24 that applies a voltage between the electrodes 42 and 43 via the cable 23. Has been.

  The electrode 42 is formed of a plate-like flat electrode, is fixed in the dielectric 41, and one surface is exposed on the same surface as the surface of the dielectric 41. In addition, the surface of the dielectric 41 from which the electrode 42 is exposed is preferably configured as a flat surface. Further, the electrode 42 may be buried in the dielectric 41 without being exposed to the surface of the dielectric 41. The electrode 42 may be provided so as to protrude from the surface of the dielectric 41. Further, the electrode 42 may be fixed to the surface of the dielectric 41. When the fluid flows on the plane of the dielectric 41, the electrode 42 is exposed on the same plane as the surface of the dielectric 41 or embedded in the dielectric 41 so as not to disturb the flow of the fluid. It is preferable. The shape of the electrode 42 is not limited to a plate shape, and may be, for example, a bar shape such as a circle or a rectangle in cross section.

  The electrode 43 is formed of a plate-like flat electrode. As shown in FIG. 4, the electrode 42 differs from the surface of the dielectric 41 when the distance from the surface of the dielectric 41 is different from that of the electrode 42. The electrodes 42 are arranged opposite to the electrodes 42 so as not to overlap each other, that is, offset from the electrodes 42 in a direction horizontal to the surface of the dielectric 41 through which the airflow flows. Note that the electrodes 42 and 43 are separated to such an extent that dielectric breakdown does not occur in the range of the voltage applied between the electrodes. Further, the shape of the electrode 43 is not limited to a plate shape, and may be, for example, a bar shape such as a circle or a rectangle in cross section. Moreover, the same shape as the electrode 42 may be sufficient. In addition, the material which comprises the electrodes 42 and 43 and the dielectric material 41 is the same as the case of 1st Embodiment.

  Here, it is good also as an airflow generation unit which comprises the dielectric material 41 by a block and is provided with the above-mentioned electrode structure. By adopting the air flow generation unit structure, this air flow generation unit can be used, for example, by embedding it in a site where an air flow is desired to be generated, handling is easy, and the range of usage can be expanded.

  Next, the operation of the airflow generation device 40 will be described.

  When a voltage is applied between the electrodes 42 and 43 from the discharge power supply 24 and a potential difference equals or exceeds a certain threshold value, a dielectric barrier discharge is generated between the electrodes 42 and 43. Here, since the direction of the electric field is along the surface of the dielectric 41, the generated air flow 45 flows in a direction along the surface of the dielectric 41 in the direction from the electrode 42 to the electrode 43.

  As described above, according to the airflow generation device 40 of the second embodiment, an airflow can be generated in a predetermined direction along the surface of the dielectric 41. Further, by integrating the electrodes 42 and 43 with the dielectric 41, the rigidity of the electrodes 42 and 43 can be increased, and an electrode having a strength that can withstand various applications can be configured.

  Next, an application example using the airflow generation device 40 of the above-described second embodiment will be described below. Here, an example in which the airflow generation device 40 is used for a blade, a moving body, a heat exchange device, a micromachine, and a gas processing device is shown. In addition, the use application of the airflow generator of this invention is not restricted to these. Moreover, you may provide the air flow generation unit which united it instead of the air flow generation device 40. FIG.

  Here, as an apparatus that can be used to influence the flow of the surface of a blade, for example, in addition to the above-described airflow generator of the present invention, a piezoelectric element such as a piezo element or the like, or a sound wave generator is used. And a mechanical vibration device, a heating device using a nichrome wire, a thermal vibration device using a cooling device, and the like, a device for ejecting or sucking air from a fine hole formed in the surface, and emitting or absorbing sound waves. However, the mechanism with a mechanical drive unit cannot avoid the problem of deterioration or failure, and the thermal vibration generator has a slow drive time constant, so it cannot follow the fluctuation of the air current, and it can eject or suck from the pores. The apparatus to be performed has a problem that the structure is complicated because it is necessary to form cavities and flow paths inside the structure, and all of them lack practicality compared to the airflow generation apparatus using the discharge of the present invention.

(Application to wing 50)
Here, an example in which the airflow generation device 40 is used as a means for controlling the aerodynamic characteristics of the blade 50 will be described. FIG. 5 is a perspective view schematically showing a blade 50 provided with an airflow generation device 40 on the blade upper surface side. 6A to 6C are diagrams schematically showing a cross section of the blade 50 in order to explain the flow of the airflow on the blade upper surface. The wings include, for example, windmill wings, airplane wings and propellers, turbine wings, blower wings, and the like.

  As shown in FIG. 5, the airflow generation device 40 is fixed to the blade 50 so that the surface of the electrode 42, that is, the surface of the airflow generation device 40 is flush with the upper surface of the blade. By disposing the airflow generation device 40 in this way, a dielectric barrier discharge can be generated on the surface of the blade 50 and the airflow 51 can be generated. Here, the airflow generation device 40 is disposed so as to generate an airflow 51 in parallel and in the same direction as the fluid (air) flowing on the upper surface of the blade 50. Moreover, since the airflow generation device 40 is arranged so that the surface thereof is flush with the blade upper surface, the fluid flowing on the blade upper surface is not disturbed by the airflow generation device 40 main body.

As shown in FIG. 6, in the blade 50, when the blade 50 has a predetermined angle of attack with respect to the air flow, the flow velocity on the blade upper surface increases, the static pressure decreases by Bernoulli's theorem, and the blade upper surface sucks up. It is done. Further, the flow velocity on the blade lower surface decreases, the static pressure increases, and the blade lower surface is pushed up. Therefore, the blade 50 receives the lift L with respect to the direction perpendicular to the flow. This lift L is expressed by the following equation (2).
L = 1/2 · ρ · V · C _L · S Equation (2)

Here, ρ is the gas density, V is the gas flow velocity, S is the blade area, and _CL is the lift coefficient. C _L is gradually increased in proportion to the angle of attack alpha, since the air flow in the wing upper surface exceeds a predetermined angle of attack is peeled (see FIG. 6B), the decrease C _L Increasing the more attack To do. If it is possible to suppress the peeling of the air flow, because the high-lift can be obtained while suppressing the lowering of C _L, high efficiency blade can be realized.

  Therefore, as shown in FIG. 5, when the airflow generating device 40 is driven by being provided on the blade 50 so that the surface of the electrode 42 is flush with the blade upper surface, the fluid (air) flowing on the blade upper surface is near the boundary layer. A high-speed air flow 51 can be generated. Thereby, it becomes possible to change the velocity distribution of the boundary layer, to suppress the separation of the fluid (air), and to increase the lift coefficient.

  In this way, an air flow is generated in the boundary layer by the air flow generation device 40, and for example, by changing the flow structure of the boundary layer between the blade upper surface and the air flow, the lift coefficient on the blade upper surface is not changed without changing the structure of the blade 50. And aerodynamic characteristics such as drag coefficient can be controlled. Moreover, by controlling the voltage applied between the electrodes 42 and 43 of the airflow generation device 40, the speed of the generated airflow can be arbitrarily controlled. As a result, it is possible to control the aerodynamic characteristics in real time following the flow state of the fluid (air), and it is possible to realize an innovative aerodynamic characteristic control technique.

  In addition, technology such as riblets that suppress separation by providing fine protrusions on the object surface and transitioning from laminar flow to turbulent flow has been developed, but providing protrusions on the surface leads to an increase in resistance, Furthermore, there is a drawback that active control is impossible because of a fixed projection. On the other hand, when the flow on the blade is controlled by using the airflow generation device 40 described above, the problems such as the above-described riblets are solved, and the turbulence is generated from the laminar flow by giving a disturbance to the surface flow. A turbulent transition function for transitioning to a flow can be exhibited. As a result, it is possible to control the flow with a high degree of freedom only by electrical control without changing the shape of the blade or the like.

  In addition, for example, it is known that the flow separation on the surface of the blades causes a large-scale separation by the growth of a vortex starting from a micro vortex randomly generated on the surface. Therefore, a plurality of airflow generating devices 40 that can be controlled independently are arranged on the surface of the blade, and similarly, a plurality of surface pressure sensors, velocity sensors, vorticity sensors, etc. arranged on the surface, Fluorescence from the applied pressure-sensitive paint is photographed with a remote camera, and vortices that are randomly generated locally are detected by a method such as sensing based on the photographed image, and the air flow generator 40 in the vicinity is activated. And an air flow may be generated. As a result, the growth of micro vortices can be inhibited and large-scale separation can be prevented from occurring. In this case, the plurality of airflow generation devices may be individually controlled, or may be controlled for each group by setting the airflow generation devices located in a certain surface area as a group. These control methods are arbitrarily set according to the scale of the flow structure existing on the surface, and the above-described control can be easily performed in the airflow generator of the present invention that can generate an airflow by electrical control. . Note that the method for detecting vortices is not only determined based on information measured using a sensor or the like, but also determined using information stored in advance in a database or the like based on operating conditions. May be.

  Moreover, you may utilize the airflow generator 40 in combination with fluid control apparatuses other than the technique which concerns on this invention, such as a flap. For example, a fluid control device having a mechanical drive unit copes with a long time constant variation, and a short time constant variation is dealt with by an air flow generation device 40 by discharge. It is possible to realize control that effectively utilizes the characteristics of

  In addition to the above-described application to the wing, the airflow generation device 40 is generally applied to fluid equipment that performs a function of conversion between fluid energy and other energy by deflecting the flow by the wing. Is possible. For example, the airflow generation device 40 can be applied to a turbo fluid device that is a fluid device. Turbo-type fluid equipment includes a prime mover and a driven machine. The prime mover is a gas turbine, a steam turbine, a windmill, etc. The driven machine is a pump (such as a centrifugal pump or an axial flow pump), a blower, or a compressor (centrifugal compression). Application to equipment such as a machine and an axial flow compressor) is possible. For example, the airflow generation device 40 is provided at a predetermined position on the surface of a blade that constitutes a part of these devices, and aerodynamic characteristics such as a lift coefficient and a drag coefficient on the blade surface can be controlled.

(Application to moving body 60)
Here, an example in which the airflow generation device 40 is used as a means for controlling the aerodynamic characteristics of the moving body 60 is shown. The moving body includes an arbitrary object that moves in a gas such as an aircraft, a missile, a railway, and an automobile. FIG. 7 is a diagram schematically showing a cross section of a part of the moving body 60 having the airflow generation device 40 on the front side surface.

  As shown in FIG. 7, the airflow generation device 40 is fixed to the left and right side surfaces of the moving body 60 so that the surface of the electrode 42, that is, the surface of the airflow generation device 40 is flush with the side surface of the moving body 60. Yes. By disposing the airflow generation device 40 in this way, a dielectric barrier discharge can be generated on the side surface of the moving body 60 and the airflow 61 can be generated. Here, the airflow generation device 40 is disposed so as to generate the airflow 61 in parallel and in the same direction as the fluid (air) flowing through the side surface of the moving body 60. Moreover, since the airflow generation device 40 is disposed so that the surface thereof is flush with the side surface of the moving body 60, the fluid flowing on the side surface of the moving body 60 is disturbed by the airflow generation device 40 main body. Absent.

  Drag due to friction with the gas is generated on the surface of the moving body 60 propelled in the gas. If the flow is separated at a part of the side surface of the moving body 60 to cause an imbalance in the drag, stability in the lateral direction (left-right direction) with respect to the traveling direction is impaired. Therefore, as shown in FIG. 7, when the airflow generation device 40 is provided on the side surface of the moving body 60 and driven, a high-speed airflow 61 can be generated near the boundary layer of the gas flowing on the side surface of the moving body 60. Thereby, the velocity distribution of the boundary layer can be changed, gas separation can be suppressed, and the drag coefficient can be changed. Due to this action, the lateral stability of the moving body 60 can be maintained by generating the air flow with the air flow generating device 40 so as to reduce the left and right drag difference with respect to the traveling direction of the moving body 60. In addition, the path of the moving body 60 can be changed by controlling the drag difference between the left and right with respect to the traveling direction of the moving body 60 by the airflow generation device 40.

  In this way, the airflow is generated in the boundary layer by the airflow generation device 40, and the movement of the boundary layer between the side surface of the moving body 60 and the airflow is changed without changing the structure of the moving body 60, for example. Aerodynamic characteristics such as drag coefficient in the body 60 can be controlled. Moreover, by controlling the voltage applied between the electrodes 42 and 43 of the airflow generation device 40, the speed of the generated airflow can be arbitrarily controlled. As a result, it is possible to control the aerodynamic characteristics in real time following the flow state of the fluid (air), and it is possible to realize an innovative aerodynamic characteristic control technique.

  Here, a high-speed aircraft and a short-range take-off and landing aircraft will be taken as an example of the moving body 60, and an example in which the airflow generation device 40 according to the present invention functions as an airflow control device will be described.

(1) Application to high-speed aircraft (use of peeling suppression and friction reduction functions)
For example, in an aircraft flying in a transonic region, air becomes a compressible gas, and shock waves are generated at various positions on the surface of the aircraft. For this reason, various obstacles occur in the stability and maneuverability of the aircraft.

  Therefore, the airflow generation device 40 according to the present invention is provided at various positions on the surface of the aircraft, in particular, the portion where the shockwave is likely to be generated, and further, it is detected that the shockwave is generated corresponding to each airflow generation device 40. A detection device such as a surface pressure sensor is provided. Then, by operating the airflow generation device 40 corresponding to the portion where the generation of the shock wave is detected, the generation of the shock wave can be suppressed or the propagation direction of the shock wave can be changed. In this way, the aerodynamic characteristics can be immediately controlled in accordance with fluctuations in the unstable airflow caused by the shock wave, so that stable flight is possible.

  Also, in supersonic and hypersonic moving bodies, as the flight speed increases, heat damage due to friction with air gradually increases, and in particular, an airflow control device having an operating part that operates mechanically has its operating part. Problems arise in the lubricity and heat insulation properties of the product, making it unusable. Aircraft resistance can be divided into shape resistance (pressure resistance), induction resistance, wave resistance, and friction resistance. Of these, friction resistance accounts for almost half of the resistance. Reducing the frictional resistance suppresses the generation of heat due to the friction described above, and further improves the fuel consumption rate of the aircraft.

  Even when such a thermal obstacle, that is, when the temperature is high, the dielectric 41 is made of a heat-resistant material such as ceramics, and the electrodes 42 and 43 are made of a heat-resistant metal such as stainless steel or Inconel (manufactured by Inco). The airflow generation device 40 according to the invention can be applied. In addition, the airflow generator 40 can be operated to suppress or delay the transition of the airflow from a smooth laminar flow with a low frictional resistance to a turbulent flow with a high frictional resistance on the surface of the wing. Can be reduced. Further, as described above, the airflow generator 40 is provided at a predetermined position on the surface of the supersonic aircraft main wing, horizontal tail, vertical tail, etc. to generate air current in the boundary layer, for example, suppression of gas separation. By changing the flow structure of the boundary layer between the blade upper surface and the airflow by means of the above, aerodynamic characteristics such as lift coefficient and drag coefficient of the blade can be controlled without changing the structure of the blade.

(2) Application to short-range take-off and landing aircraft (use of peeling control and friction reduction function)
Since short-range take-off and landing aircraft and the like are equipped with powerful high lift devices that use the wake or bleed of the propeller or jet, the weight of these devices increases and the economy is often impaired.

  Therefore, the airflow generation device 40 according to the present invention is installed at a predetermined position on the blade surface or the body surface. As a result, it is possible to improve the lift, reduce the burden on the high lift device, and reduce the size of the device. In addition to the short-range take-off and landing aircraft (STOL aircraft) (including QTOL aircraft) described above, the airflow generator 40 is used for aircraft wings and aircraft such as vertical take-off and landing aircraft (VTOL aircraft) and normal take-off and landing aircraft (CPOL aircraft). You may install in the predetermined position of the surface.

  As a result, it is possible to improve the lift of a short-range take-off and landing aircraft that requires a large lift during take-off and landing. In addition, as described above, the airflow generation device 40 is provided at a predetermined position on the surface of the wing of the aircraft main wing, horizontal tail wing, vertical tail wing, etc. to generate an air flow in the boundary layer, for example, by suppressing gas separation. By changing the flow structure of the boundary layer between the blade upper surface and the airflow, aerodynamic characteristics such as lift coefficient and drag coefficient of the blade can be controlled without changing the structure of the blade.

  The airflow generation device 40 described above is characterized by controlling the surface flow, and can be applied to various devices that are affected by the surface flow other than the moving body described above.

  For example, in a fluid displacement device that includes a prime mover such as a motor or a cylinder, or a driven device such as a pump or a compressor, it controls the flow or circulation of the air flow inside the volume, or flows in a part where a vortex is generated. It can be used for applications such as rectification.

  Here, the flow control in the cylinder of the engine will be specifically described as an example. In order to improve the performance of the engine which is an internal combustion engine, it is necessary to optimize the airflow of the air-fuel mixture fed into the cylinder. The airflow properties are influenced by the shape of the intake pipe and valve, and affect the combustion efficiency and pressure loss.

  For example, there is a portion where the diameter of the tube suddenly expands at a location where the air flows into the cylinder from the intake pipe, and the generation of vortex in that portion increases the pressure loss and decreases the efficiency. In addition, if the air-fuel mixture flows biased toward the cylinder surface, the combustion efficiency at the center of the cylinder decreases, and therefore it is preferable to generate a flow that is uniformly mixed inside the cylinder. Therefore, the airflow generation device of the present invention is installed in the sudden expansion portion of the cylinder to suppress the generation of vortices, or it is installed on the inner wall surface of the cylinder to generate an airflow so as to disturb the current flow near the wall surface. Thus, the combustion efficiency and pressure loss can be optimally controlled. In particular, the airflow generation device of the present invention that can control the flow only by an electrical factor is excellent for airflow control with respect to a complicated flow that changes every moment like the inside of a cylinder.

  Moreover, since the airflow generation device 40 is present in the flow other than the fluid device, it can be applied to general devices that are affected by the flow. For example, it can be applied to a lifting device such as an elevator that moves in a closed space if it is a moving body, and to a building such as a bridge, steel tower, or building if it is a non-moving body. The airflow generation device can mitigate the mechanical influences of traveling winds and natural winds that change in a complex manner in these devices and buildings.

  Here, application to a high-rise building will be specifically described as an example. Around the high-rise buildings, there are natural winds that are totally random in time and direction, and the buildings receive wind loads from those winds. The wind acts torsional force on the building by the frictional force generated by the separation of the corners and protrusions of the building to form a vortex or the flow along the outer wall surface. Such a wind causes noise such as shaking of the building, application of a load to the structure, generation of building wind, and wind noise. Then, the airflow generator 40 of this invention is installed in the corner | angular part and protrusion part of a building, and the load to a structure can be suppressed by suppressing peeling of the natural wind in a corner | angular part or protrusion part. Moreover, by installing the airflow generation device of the present invention on the surface of the outer wall, it is possible to prevent the generation of torsional force on the building, and the flow according to the wind generated randomly in time and space. Control becomes possible.

  Furthermore, the airflow generation device 40 may be provided on the surface of a material transportation pipeline or duct tube to control the flow of fluid flowing through the pipeline or duct tube. By providing the airflow generation device 40 in this manner, for example, it is possible to suppress the generation of vortices at the inlet of the pipeline.

  Here, the case where it applies to the run-up section of the entrance of a pipe line is demonstrated concretely as an example. As for the velocity distribution when entering the pipe through the nozzle from a wide space, the velocity distribution near the inlet is almost uniform and the boundary layer is very thin. This boundary layer increases in thickness as it goes downstream. In this run-up section, since the velocity gradient near the pipe wall is large, the frictional stress increases and a large pressure loss occurs. Therefore, if the airflow generation device 40 of the present invention is provided on the pipe wall in the run-up section and the airflow is controlled so as to reduce the velocity gradient, the pipe friction coefficient can be reduced. For example, a cylindrical airflow generator 40 made of a dielectric and an electrode is provided on the tube wall, and a high frequency voltage is applied between the cover (metal) and the electrode. The coefficient of friction can be reduced by improving the speed near the wall surface and relaxing the speed gradient by the airflow generated from the airflow generator.

  Moreover, you may apply the airflow generator 40 to the apparatus which produces | generates a flow with respect to the exterior like an air conditioning apparatus, for example. There is an air conditioner equipped with a rectifying blade or the like that is located at the center of the flow path, not at the wall surface of the flow path, and that generates a rectifying action at the outlet of the air conditioner. For example, by providing the airflow generation device 40 at a predetermined position on the surface of the rectifying blade, it is possible to prevent separation of the flow from the surface of the rectifying blade, and an efficient rectifying effect is obtained. Also, in the cooling equipment that is an air conditioner, when the rectifying blades are used as described above, the room air is drawn toward the rectifying blades due to the backflow caused by the vortex formed in the rectifying blade parts, and the part that has become cold is touched. Condensation may occur. Therefore, by providing the airflow generation device 40 of the present invention at a predetermined position on the surface of the rectifying blade as described above, it is possible to prevent the generation of vortices and prevent condensation at the outlet of the cooling device.

(Application to heat exchanger 70)
Here, an example in which the airflow generation device 40 is used as a means for controlling the heat transfer characteristics of the heat exchange device 70 is shown. Specifically, an example in which the airflow generation device 40 is used as a means for promoting turbulent flow is shown. FIG. 8 is a perspective view schematically showing a heat exchange device 70 provided with the airflow generation device 40 on the heat transfer surface 71.

  As shown in FIG. 8, the airflow generation device 40 is fixed to the heat exchange device 70 so that the surface of the electrode 42, that is, the surface of the airflow generation device 40 is flush with the heat transfer surface 71 of the heat exchange device 70. ing. By disposing the airflow generation device 40 in this manner, a dielectric barrier discharge can be generated on the heat transfer surface 71 of the heat exchange device 70 and the airflow 72 can be generated. Here, the airflow generation device 40 is disposed so as to generate the airflow 72 in parallel and in the opposite direction to the gas 73 flowing through the heat transfer surface 71 of the heat exchange device 70. Note that the airflow generation device 40 may be arranged so as to generate the airflow 72 in parallel and in the same direction as the gas 73 flowing through the heat transfer surface 71 of the heat exchange device 70.

  The heat exchange device 70 exchanges heat quantity between the gas 73 flowing outside the heat transfer surface 71 and the refrigerant 74 flowing inside the heat exchange device 70 via the heat transfer surface 71. The airflow 72 generated by the airflow generation device 40 flows in the opposite direction to the flow direction of the gas 73 flowing through the heat transfer surface 71 and collides with the gas 73, thereby causing disturbance in the boundary layer near the heat transfer surface 71 and heat. Can facilitate communication.

  As described above, the air flow is generated in the boundary layer by the air flow generation device 40, and the structure of the heat exchange device 70 is changed by changing the flow structure of the boundary layer between the heat transfer surface 71 of the heat exchange device 70 and the air flow, for example. The heat transfer characteristics on the heat transfer surface 71 can be improved without changing. Moreover, the heat transfer characteristic can be arbitrarily controlled by controlling the voltage applied between the electrodes 42 and 43 of the airflow generation device 40.

  The above-described use of the airflow generation device 40 as means for promoting turbulent flow is not limited to a heat exchange device, and it is preferable to promote heat transfer, and functions such as heating, cooling, condensation, and boiling are used. It can be used for heat transfer equipment in general. The airflow generation device 40 can be used as a heat transfer characteristic control means by being installed at a predetermined position such as a cooling fin for cooling an element of a computer or a heat exchange fin of an air conditioner. Thereby, it is possible to improve heat transfer characteristics such as cooling fins and heat exchange fins.

(Application to micromachine 80)
Here, an example of the case where the airflow generation device 40 is used as a drive mechanism of the micromachine 80 is shown. Specifically, an example in which the airflow generation device 40 is used as thrust generation means will be shown. FIG. 9 is a perspective view schematically showing a micromachine 80 provided with the airflow generation device 40 on the side surface and the upper surface.

  As shown in FIG. 9, the airflow generation device 40 is fixed to the micromachine 80 so that the surface having the electrode 42 is flush with the side surfaces 81 a, 81 b, 81 c, 81 d, or the upper surface 82 of the micromachine 80. . On the side surfaces 81a, 81b, 81c, 81d, the airflow generation device 40 is provided below the side surfaces 81a, 81b, 81c, 81d so as to generate an airflow vertically downward. In addition, at least four airflow generation devices 40 are provided on the upper surface 82, and each airflow generation device 40 generates airflows in different vertical directions in the horizontal direction on the upper surface 82 and toward the outside of the micromachine 80. Are arranged as follows.

  Further, as described above, the voltage may be applied to the electrodes 42 and 43 of the airflow generation device 40 provided in the micromachine 80 from the discharge power supply 24 via the cable 23, but as shown in FIG. It is preferably applied from outside without contact. As a method of applying a voltage to the electrodes 42 and 43 in a non-contact manner, for example, a photoelectric conversion element 87 is installed on the side surface of the micromachine 80, and the laser light 86 emitted from the laser generator 85 is applied to the photoelectric conversion element 87. For example, a method of supplying energy by irradiating and applying a voltage to the electrodes 42 and 43 may be used. Thereby, the micromachine 80 can be driven without being restricted by a cable or the like.

  Further, as another method of applying a voltage to the electrodes 42 and 43 in a non-contact manner, for example, a thermoelectric conversion element is installed on the side surface of the micromachine 80, and the thermoelectric conversion element is irradiated with infrared rays or the ambient temperature is increased. Thus, a method of applying a voltage to the electrodes 42 and 43 can be used. Furthermore, a coil or antenna is provided on the side surface of the micromachine 80, and other electromagnetic waves such as microwaves and millimeter waves are applied to the coil or antenna, and an induced voltage generated in the coil or antenna is applied between the electrodes 42 and 43. Good.

  As described above, in the micromachine 80 provided with the airflow generation device 40, for example, when the airflow generation devices 40 provided on the side surfaces 81a, 81b, 81c, and 81d are driven, the airflow 83 for levitation is generated. A micromachine emerges. Further, when the micromachine 80 is flying, for example, when one of the airflow generation devices 40 provided on the upper surface 82 is driven, the micromachine moves in the direction opposite to the flow direction of the airflow 84. In addition, when the micromachine 80 is flying, the micromachine can be moved in all directions by appropriately driving each airflow generation device 40 provided on the upper surface 82. In addition, by controlling the voltage applied between the electrodes 42 and 43 of the airflow generation device 40, the speed at which the micromachine is moved can be arbitrarily controlled.

  The above-described airflow generation device 40 that functions as thrust generation means is not limited to a micromachine, and can be used for general equipment that uses airflow as thrust. The airflow generation device 40 can be used as a thrust generation means, for example, installed at a predetermined position on the surface of a flying object such as a rocket or a missile or an unmanned aircraft. Thereby, it is possible to add a thrust to a flying object such as a rocket or a missile or to add a thrust for steering.

(Application to gas processing equipment 90)
Here, an example in which the airflow generation device 40 is used for an active species generation mechanism, a blower mechanism, and a diffusion / mixing mechanism of the gas processing device 90 is shown. FIG. 10 is a perspective view schematically showing an active species generation unit of a gas processing device 90 provided with the airflow generation device 40. The gas processing device 90 includes, for example, a deodorizing device or a sterilizing device that processes malodorous substances with ozone generated by discharge, a particulate matter reducing device that burns soot by NO ₂ generated by discharging.

  As shown in FIG. 10, a plurality of airflow generation devices 40 are stacked on the active species generation unit 100 of the gas treatment device 90 at a predetermined interval. Here, each airflow generation device 40 is disposed so as to generate the airflow 101 in one direction in the active species generation unit 100. The active species generated by the dielectric barrier discharge in the active species generating unit 100 is guided to a gas processing unit (not shown) that processes the non-processing gas by the air flow 101 generated by the dielectric barrier discharge. As described above, the airflow generation device 40 has both functions of an active species generation mechanism that generates active species by discharge and a blower mechanism that blows the active species to the gas processing unit.

  In the conventional gas processing apparatus, a structure in which the active species generated by the discharge is guided to the gas processing unit by a fan or the like has been used. However, by including the gas processing apparatus 90 according to the present invention, as described above, the active species Since the production | generation part 100 is provided with the function of both an active species production | generation function and a ventilation function, the compactization of an apparatus, power saving, and the reduction of manufacturing cost can be aimed at.

  As described above, by using the airflow generation device 40 as an active species generation function or an air blowing function, a chemical reaction device that generally causes some chemical reaction to gas molecules existing in the fluid can be used. . Further, the airflow generation device 40 can be used as a diffusion / mixing mechanism. For example, the airflow generator 40 can be used for the purpose of changing the diffusion rate and mixing rate by controlling the flow of the fluid and controlling the reaction rate of the total chemical reaction. Specifically, it can be used for a combustor, a gas mixing device, a sterilizer, a chemical process reactor, and the like.

  When the airflow generation device 40 is used in the combustor, it can be used as a mechanism for controlling a part of the flow in the combustion field, for example. In order to stabilize the flame, it is preferable to burn the mixture ratio of fuel and oxidant in the vicinity of the stoichiometric ratio (equivalent ratio is 1), but in order to suppress harmful components such as NOx contained in the exhaust gas. In recent years, combustors using a combustion method in which lean combustion is performed as a whole (overall) have become mainstream. For example, in diffusion combustion in which fuel and oxidant are individually supplied to the combustion region and the fuel and oxidant are combusted in the combustion region, the equivalence ratio is locally determined in the flow field in the combustor formed according to the operating conditions. There may be a region where is around 1. In such a region, the flame temperature becomes high and the generation of NOx is promoted. When such a region exists in the vicinity of the wall surface of the combustor, the airflow generation device 40 is provided on the wall surface of the combustor. Then, the air flow generator 40 is operated according to the operating conditions, and a flow is formed so that the surrounding oxidant is involved in a region where the equivalence ratio is near 1, and the fuel concentration is reduced, that is, the equivalence ratio is set. It can be burned in a small and lean state. Further, by providing the airflow generator 40 on the wall of the combustor so as to promote turbulence, that is, to disturb the flow, it is possible to promote mixing in the vicinity of the wall where mixing of the fuel and the oxidant is difficult to be promoted. it can.

  In addition, the discharge can crack the fuel materials to produce lower molecular weight combustible materials, and these materials contribute to the combustion to promote combustion. As a result, a combustor can be realized that can be downsized and have high combustion efficiency. In addition, when using the airflow generator 40 in a combustor, since it becomes high temperature, it is preferable to comprise the dielectric material 41 with heat resistant materials, such as ceramics, and to comprise the electrodes 42 and 43 with a heat resistant metal.

  When the airflow generation device 40 is used in a gas mixing device, it can be used as a mechanism for promoting gas mixing, for example, by generating vortices or turbulent flows. For example, in a coaxial double tube nozzle configured for the purpose of mixing fuel and air, conventionally, in order to promote the mixing, a method such as providing guide blades for forming a swirling flow inside the outer nozzle is the mainstream. Met. However, mechanically structured mixing devices do not function effectively only at predetermined flow conditions. Therefore, the airflow generation device 40 of the present invention is provided on the inner wall side of the outer nozzle or the outer wall side of the inner nozzle, and the airflow is generated so as to generate turbulent flow and vertical vortex near the wall surface. As a result, vortices and turbulence are generated in the vicinity of the boundary between the inner side and the outer side, and when there is no partition between the two, mixing between the two fluids abruptly occurs due to the action of these vortices. In particular, since the vortex has the function of transporting material in its axial direction, the generation of a vortex having an axis perpendicular to the interface of the two fluids effectively transports one fluid into the other fluid and mixes it. Promoted.

  Even when the airflow generator 40 is used in the sterilization device, the same structure as the case where the airflow generator 40 is used in the gas mixing device described above is used as a mixing promotion mechanism by generating, for example, vortex or turbulent flow. Can do. In the gas mixing apparatus, the case where fuel and air are mixed has been described. However, in a sterilization apparatus, for example, ozone having a sterilizing action is used instead of fuel, and gas to be sterilized instead of air is a coaxial double tube. It flows through each flow path of the nozzle and is mixed.

  When the airflow generator 40 is used in the chemical process reactor, the chemical process reaction in which diffusion between substances has conventionally been a rate-limiting condition with the same configuration as when the airflow generator 40 is used in the gas mixing device described above. In the vessel, the chemical reaction can be promoted by forced mixing by vortex or turbulent flow. In general, a chemical process reactor often causes a reaction in a huge reaction layer, but stagnation or stagnation may occur in the vicinity of the corner or wall of the container, thereby reducing the overall reaction efficiency. In such a case, the chemical reaction can be promoted by providing the airflow generation device 40 in the vicinity of stagnation or stagnation. In addition, since a chemical reaction active species can be generated from a chemical substance by discharge, the inlet substance considered in the conventional chemical process can be changed, and for example, low temperature activation of a catalytic reaction can be realized. . In the case where the airflow generator 40 is used in the chemical process reactor, the dielectric 41 is made of a corrosion-resistant material such as ceramics and the electrode 42 in order to make it difficult to receive a chemical reaction such as corrosion by the target chemical substance. , 43 are preferably made of a corrosion-resistant metal or the like.

  Note that the air blowing function can be used not only for transporting gas but also for transporting powder and the like.

(Application to other devices)
As described above, the airflow generation device 40 according to the present invention has, for example, a separation suppressing function in application to a blade, a friction reducing function in application to a moving body, for example, a turbulence promoting function in a heat exchanger, It has been described that a micromachine has a thrust function, for example, and a gas processing apparatus has an active species generation function, a blowing function, and a diffusion / mixing function. Here, it will be described that the provision of the airflow generation device 40 according to the present invention provides the effect of reducing noise and vibration, suppressing fluid leakage, and the application of the airflow generation device 40 to other devices. .

  For example, in automobile noise, vortices generated by front pillars and mirrors are said to be the main cause of vehicle interior noise. The air flow generation device 40 is provided at a predetermined position on the front pillar and the mirror surface, and the air flow generated by the air flow generation device 40 is controlled according to the vehicle speed, thereby suppressing separation or the flow from the front pillar and the flow from the mirror. By controlling the direction, the interference between the two can be suppressed. As a result, it is possible to reduce noise caused by vortices generated in the front pillar and the mirror.

  In addition, the noise when the vehicle is driven with the sunroof opened is Helmholtz resonance generated by the vehicle compartment acting as a resonance box. By providing an airflow generation device 40 at a predetermined position on the surface near the opening of the sunroof and controlling the airflow generated by the airflow generation device 40, the periodic structure of the flow near the opening is destroyed and noise is reduced. Is possible.

  In addition, fluid vibration represented by Karman vortex causes vibration to the structure placed in the airflow, and may lead to destruction of the structure depending on the resonance state. Separation can be suppressed by installing the airflow generation device 40 near the separation point of the fluid from the structure and controlling the airflow generated by the airflow generation device 40. Thereby, the fluid vibration in the structure can be reduced.

  In addition, since the loss due to leakage of working fluid or the like cannot be ignored in the gap between the turbine blade and the casing, a labyrinth seal or brush seal is provided to suppress leakage of the working fluid or the like. However, friction with the labyrinth seal or brush seal or wear of the labyrinth seal or brush seal due to the provision of a labyrinth seal or brush seal in the gap as described above is a problem. Therefore, the airflow generation device 40 is disposed in the gap between the turbine blades and the casing or in the vicinity thereof, and the direction of the working fluid flowing out from the gap is opposite to the working fluid from the gap or toward the gap. Thus, by generating the air flow from the air flow generation device 40, it is possible to suppress the leakage of the working fluid from the gap between the blades of the turbine and the casing without problems such as friction and wear. In particular, in the case of a turbine, it is effective to apply this configuration to a stationary blade. Moreover, by providing the airflow generation device 40, a function as a leakage suppression mechanism capable of electrically controlling the generated airflow can be exhibited.

  In addition, it is known that the characteristics of the airfoil are greatly affected by the degree of turbulence in the mainstream, particularly near the critical Reynolds number. Therefore, in a wind tunnel or the like for performing an airfoil test, various tests have been made to give turbulence to the mainstream because the test is performed under conditions close to those of an actual machine. However, since the conventional method of imparting disturbance to the mainstream is often performed mainly using a mechanical drive unit, it has been impossible to give a disturbance of a scale shorter than the drive time constant of the mechanical drive unit. Therefore, for example, in each honeycomb lattice constituting the rectifier provided in the upstream portion of the wind tunnel, an independently controllable airflow generator 40 is installed to generate a random airflow at each lattice point. Thus, it is possible to configure a wind tunnel that can generate an air current having a high degree of turbulence. As a result, the airflow generation device 40 can be used as a turbulence generation mechanism, and optimal airflow control can be realized by controlling electrical characteristics such as voltage, frequency, waveform, and duty ratio.

  In addition, a method has been studied in which longitudinal vortices having a vortex axis in the flow direction are generated in a low Reynolds number region or the like, thereby realizing reattachment of a separated flow or promotion of mixing by a secondary flow. However, the conventional vertical vortex generating mechanism has been disadvantageous in that active control is impossible because the mainstream is mainly due to jets from fine holes or mechanical structures such as fine protrusions. Therefore, by arranging the airflow generation device 40 so as to generate the airflow component in the direction perpendicular to the surface, a vertical vortex generation mechanism with a high degree of freedom can be achieved only by electrical control without changing the shape of the object. Can be realized.

  When using the airflow generation device 40 as a vertical vortex generation mechanism, it is effective to arrange electrodes so as to generate an airflow component in a direction perpendicular to the surface, but it induces a flow along the surface. Even in this case, since an area where the flow from above is drawn near the electrode end is formed, a vertical vortex can be generated (see FIG. 13C described later).

(Example)
Next, various mechanisms and operations of the airflow generation device 40 described above will be specifically described based on examples.

(Operation of the airflow generator in an environment other than atmospheric pressure)
Here, the airflow generation device according to the present invention has a greater degree of freedom and optimal airflow control than airflow control mechanically even in airflow control in an environment other than atmospheric pressure, such as under reduced pressure. Explain what is possible.

  As a device that requires airflow control in a reduced pressure environment, for example, there is a space device. Among space devices, for example, in rockets, space vehicles, space transport aircraft, and devices that move between the earth and space, it is necessary to move in a region where the gas density changes greatly. It is impossible to supplement the aerodynamic characteristics with respect to such a wide range of fluid conditions only by the device of the shape. However, this can be made possible by providing the airflow generator according to the present invention and performing electrical control.

  Although the form of discharge varies depending on the air density, optimal airflow control can be realized under various density conditions by performing optimal voltage control at each air density. Note that the usage application in a reduced pressure environment is not limited to space equipment, and includes various manufacturing processes for semiconductors, the final stage of a steam turbine, and the like. In addition, the airflow control other than the atmospheric pressure is not limited to the reduced pressure environment, but the airflow control in the pressurized environment as in the first stage of the steam turbine can be considered, but the voltage control according to the discharge form determined by the pressure condition is performed. By doing so, the same optimal control as in the decompressed state is possible.

  FIG. 11A is a plan view schematically showing an airflow generation device for observing the form of discharge when the pressure condition is changed. FIG. 11B and FIG. 11C are diagrams showing discharge modes when the pressure condition is changed. Here, the airflow generation device 10 having the configuration shown in FIGS. 1 and 2 was used as the airflow generation device, and both the electrodes 21 and 22 were formed of flat plates.

  As shown in FIG. 11A, the airflow generation device 10 uses a copper foil having a width L1 (length in the airflow generation direction) of 10 mm, a lateral M1 of 80 mm, and a thickness of 0.1 mm as the electrode 21. A copper foil having a width L2 (length in the direction of airflow generation) of 30 mm, a lateral M2 of 120 mm, and a thickness of 0.1 mm was used. Between the electrodes, an alumina flat plate having a width L3 (length in the direction of airflow generation) of 120 mm, a lateral M3 of 130 mm, and a thickness of 2 mm is used as the dielectric 20. The distance N between the airflow generation directions was set to 0 mm. Moreover, the pressure around the discharge part was set to 1027 hPa or 100 hPa, and an alternating voltage of 3 kHz (7 W) was applied to the electrodes.

  As shown in FIG. 11B and FIG. 11C, when the discharge 120 when the pressure around the discharge portion is 1027 hPa and the discharge 120 when the pressure is 100 hPa are compared, the discharge 120 spreads more when the pressure is 100 hPa. all right.

Here, the discharges 120 that are in the form of thin strings gather and spread to each other and extend in a planar shape. Near the center of the planar discharge surface, “n ⁺ (positive ion density) = n ⁻ (electron or negative ion density)” and the force cancels, but the vicinity of the boundary of the discharge surface is called a sheath, Since “n ⁺ ≠ n ⁻ ”, the momentum transfer to neutral molecules occurs and airflow is generated.

  As described above, it has been clarified that the airflow generation device 10 having the electrode structure of the present invention can discharge even under an environment other than atmospheric pressure, although there is a difference in discharge form. As a result, it has been clarified that an airflow can be generated even under an environment other than atmospheric pressure, and the airflow generating device functions. The degree of function as an airflow generator, that is, the characteristics of the generated airflow, can be controlled only by electrical characteristics such as voltage, frequency, waveform, and duty ratio, so that not only the flow rate but also the pressure changes in a complex manner. It has been found that it effectively functions as an air flow generator for various fluid devices.

(Operation of the airflow generator in a gas environment other than air)
Next, it will be described that the airflow generation device according to the present invention can form a discharge even in a gas environment other than air.

  FIG. 12 is called a Paschen curve, and is a diagram showing the spark voltage in each gas type. The spark voltage is expressed as a function of the product Pd of the pressure P and the interelectrode distance d depending on the gas type. Thus, the voltage required to generate discharge varies depending on the type of gas. Further, depending on the type of gas, there is a type in which the discharge spreads in the same manner as the discharge at low pressure. In the airflow generation device according to the present invention, only the electrical characteristics such as the voltage, frequency, waveform, and duty ratio applied to the electrode are changed according to the type of gas, thereby causing discharge according to the gas type and the airflow. Can be generated. That is, it effectively functions as an air flow generator for a fluid device in which the gas component changes in addition to the flow velocity and pressure.

  Here, examples of applications in a gas environment other than air include various manufacturing processes such as semiconductors, steam turbines, biogas processes, and space equipment that moves in an atmosphere other than the earth.

(Observation of airflow generated by the airflow generator)
FIG. 13A is a cross-sectional view schematically showing the airflow generation device 10. FIG. 13B is a diagram showing a result of observing the flow velocity distribution in the height direction of the uniform flow by the smoke wire method. FIG. 13C is a diagram showing a result of observing the flow velocity distribution in the height direction of the air flow generated by the air flow generation device 10 in the uniform flow by the smoke wire method.

  As shown in FIG. 13A, the airflow generation device 10 uses a copper foil having a width L1 (length in the airflow generation direction) of 10 mm, a width of 110 mm, and a thickness t1 of 0.1 mm as the electrode 21. A copper foil having a width L2 (length in the direction of airflow generation) of 10 mm, a width of 100 mm, and a thickness t2 of 0.1 mm was used. Between the electrodes, a quartz glass plate having a width L3 (length in the direction of airflow generation) of 120 mm, a width of 120 mm, and a thickness t3 of 1 mm is used as the dielectric 20. The distance N between the airflow generation directions was set to 0 mm. Further, a bipolar pulse of 9 kV at 3 kHz was applied to the electrode.

  As the smoke wire 130, a nichrome wire having a diameter of 0.2 mm was used, and liquid paraffin was applied to the nichrome wire as a smoke generating agent. A voltage of 250 V was applied to the smoke wire 130 for 10 ms. Then, a strobe with a light emission time of 25 μs was emitted with a delay time from voltage application. The uniform flow is an air flow having a flow velocity of 0.7 m / s.

  As shown in FIG. 13B, when the airflow generation device 10 was not operated, a velocity distribution with a velocity of 0 was observed on the flat plate surface of the dielectric 20. On the other hand, as shown in FIG. 13C, when the airflow generation device 10 is operated and the plasma 135 is generated, a jet 136 that sufficiently changes the velocity distribution of the boundary layer is formed in a region near the flat plate surface of the dielectric 20. It was done. Moreover, it turned out that the flow 137 which goes to the downward direction from the upper direction is formed so that it may flow to this jet flow 136. FIG. Although not shown here, it was observed that a similar flow was formed by the generation of the barrier discharge even when the distance N between the airflow generation directions of the electrode 21 and the electrode 22 was not 0 mm.

(Measurement of velocity distribution of airflow generated by airflow generator)
FIG. 14A is a cross-sectional view schematically showing the airflow generation device 10. FIG. 14B is a diagram showing the velocity distribution of the airflow generated by the airflow generation device 10.

  As shown in FIG. 14A, the airflow generation device 10 uses, as the electrode 21, a copper foil having a width L1 (length in the airflow generation direction) of 10 mm, a lateral M1 of 110 mm, and a thickness t1 of 0.1 mm. No. 22 was a copper foil having a width (length in the direction in which airflow was generated) of 10 mm, a lateral M2 of 100 mm, and a thickness of 0.1 mm. Between the electrodes, an alumina flat plate having a width L3 (length in the direction of air flow) of 120 mm, a width of 120 mm, and a thickness t3 of 1 mm was used as the dielectric 20. 14A, the electrode 22 is disposed so that the end surface 22a of the electrode 22 on the airflow generation direction side is flush with the end surface 20a of the dielectric 20 on the airflow generation direction side. On the other hand, the electrode 21 is arranged such that the end surface 21a on the airflow generation direction side of the electrode 21 is located at a position 10 mm away from the end surface 20a of the dielectric 20 in the direction opposite to the airflow generation direction.

  Further, as shown in FIG. 14A, the wind speed element 141 is located at a position 15 mm downstream from the end face 21 a of the electrode 21 in the air flow generation direction and at the center in the longitudinal direction (lateral M1 direction) of the electrode 22. The hot-wire anemometer 140 was arranged so as to be parallel, and the hot-wire anemometer 140 was moved in the vertical direction (perpendicular to the air flow generation direction), and the velocity distribution in that direction was measured. The hot-wire anemometer 140 is configured in a state where the wind speed element 141 is accommodated in a probe (not shown). Here, the reason why the hot-wire anemometer is disposed at a position 15 mm downstream from the end surface 21a of the electrode 21 in the air flow generation direction is to maintain electrical insulation from the electrode. The electrode has a frequency of 3 kHz, a voltage of 4.5 kV (power 0.97 W), 5 kV (power 1.04 W), 6 kV (power 2.93 W), 7 kV (power 5.09 W), 8 kV (power). 9.6 W) and an alternating voltage of 9 kV (power 11.6 W) were applied.

  As shown in FIG. 14B, under any voltage condition, it was found that the velocity distribution of the air current had a peak at a height of about 1 mm from the flat plate surface of the dielectric 20 and formed a jet. It was also found that the higher the applied voltage, the greater the discharge input power and the greater the flow velocity of the generated airflow.

(Peeling suppression effect on wings)
FIG. 15 is a cross-sectional view for explaining the phenomenon of flow separation on the blade surface. As shown in FIG. 15, the velocity distribution in the vicinity of the blade surface has a velocity of 0 on the surface 150, a velocity gradient is generated due to viscosity in the boundary layer 151, and a uniform velocity U is formed outside the boundary layer. Yes. As the thickness of the boundary layer increases, a backflow region 152 appears near the blade surface 150 and the flow is separated. Therefore, by providing the airflow generation device according to the present invention on the blade surface near the region where the backflow region 152 appears or near the region where the backflow region 152 appears, the velocity distribution of the boundary layer is changed to suppress separation. Is possible. Specifically, an airflow generator is provided on the blade surface so as to form a flow that opposes the flow direction in the reverse flow region so as to suppress the formation of the reverse flow region.

  FIG. 16 is a diagram showing the results of measuring the blade surface pressure at a predetermined position on the blade surface. The blade surface pressure is measured by providing a plurality of static pressure measurement holes at predetermined positions on the front and back surfaces of a reference blade (NACA0015, blade chord length 90 mm, blade width 100 mm), and a uniform flow of air flow with a flow velocity of 20 m / s. The surface static pressure distribution was measured. The airflow generation device according to the present invention is disposed at the front edge of the reference blade. In the arranged airflow generation device, a copper foil having a width (length in the direction of airflow generation) of 2 mm, a width of 90 mm, and a thickness of 0.1 mm is used as an upstream electrode, and a width of the downstream electrode is A copper foil having a length of 10 mm in the airflow generation direction, a width of 90 mm, and a thickness of 0.1 mm was used. As the dielectric, a polyimide film having a width (length in the direction in which airflow was generated) of 35 mm, a width of 100 mm, and a thickness of 0.1 mm was used. As a power source, a 3 kHz bipolar pulse power source was used, and a voltage of 3 kV (discharge input power was about 0.4 W) was applied. The air flow generated by the air flow generation device is generated along the surface of the reference blade in the downstream direction of the uniform flow from the upstream electrode. The angle of attack of the reference wing was set to 20 degrees. In FIG. 16, the horizontal axis indicates the ratio (X / C) between the position X in the chord direction where the static pressure measurement hole is provided and the chord length C.

  As shown in FIG. 16, when the airflow generator is operated to generate an airflow (when ON in FIG. 16), the pressure distribution changes, and in particular, the pressure distribution on the back side (blade upper surface) changes greatly. Further, it can be seen from the pressure distribution on the back side that when the airflow generator is not operated (when OFF in FIG. 16), the static pressure is increased and the flow is separated. On the other hand, when the airflow generator is activated and airflow is generated (when ON in FIG. 16), the static pressure is reduced, so that flow separation is suppressed and the flow is attached. It was.

(Voltage adjustment method)
As described above, as a voltage adjustment method, for example, a method of adjusting a voltage peak value, a voltage frequency, a voltage waveform, a duty ratio, and the like can be applied. Here, the relationship between the velocity of the airflow generated from the airflow generator when these voltages are adjusted will be described.

(1) Control example by voltage wave height As described above, FIG. 14B shows a frequency of 3 kHz, a voltage of 4.5 kV (power 0.97 W), 5 kV (power 1.04 W), 6 kV (power 2.93 W). , 7 kV (power 5.09 W), 8 kV (power 9.6 W), and 9 kV (power 11.6 W) when alternating voltage is applied, velocity distribution of the airflow generated by the airflow generator 10 is shown.

  As shown in FIG. 14B, it was found that the flow velocity of the generated airflow was larger when the applied voltage was increased and the discharge input power was increased. Thus, it was found that the speed of the generated air current can be controlled by changing the voltage wave height while keeping the frequency constant.

  Since this control is a basic control method of changing the voltage, it is suitable when the control sequence is simplified to reduce the equipment cost.

(2) Example of control by voltage frequency FIG. 17 is a diagram showing the maximum value of the velocity distribution when the voltage frequency is changed while the voltage peak value is constant. The airflow generation device used here differs from the airflow generation device 10 shown in FIG. 14A only in the sizes of electrodes and dielectrics, and the speed measurement method is the same, so the airflow generation used here is the same. The configuration of the device will be described with reference to the airflow generation device 10 in FIG. 14A.

  The airflow generation device 10 uses a copper foil having a width L1 (length in the airflow generation direction) of 2 mm, a lateral M1 of 110 mm, and a thickness t1 of 0.1 mm as the electrode 21, and a width (airflow of the airflow). A copper foil having a length in the generation direction of 10 mm, a lateral M2 of 100 mm, and a thickness of 0.1 mm was used. Between the electrodes, a polyimide film having a width L3 (length in the direction of air flow) of 35 mm, a width of 120 mm, and a thickness t3 of 0.1 mm was used as the dielectric 20. 14A, the electrode 22 is disposed so that the end surface 22a of the electrode 22 on the airflow generation direction side is flush with the end surface 20a of the dielectric 20 on the airflow generation direction side. On the other hand, the electrode 21 is arranged such that the end surface 21a on the airflow generation direction side of the electrode 21 is located at a position 10 mm away from the end surface 20a of the dielectric 20 in the direction opposite to the airflow generation direction. Further, as shown in FIG. 14A, the wind speed element 141 is located at a position 15 mm downstream from the end face 21 a of the electrode 21 in the air flow generation direction and at the center in the longitudinal direction (lateral M1 direction) of the electrode 22. The hot-wire anemometer 140 was arranged so as to be parallel, and the hot-wire anemometer 140 was moved in the vertical direction (perpendicular to the air flow generation direction), and the velocity distribution in that direction was measured.

  In this measurement, the voltage distribution (4.2, 4.6, 5 kV) is constant, and the speed distribution when the voltage frequency is changed to 2, 4, 6, 8, 10 kHz for each voltage peak value. The maximum value is shown in FIG. Note that the horizontal axis of FIG. 17 indicates the discharge input power value when the voltage frequency is changed to 2, 4, 6, 8, 10 kHz with respect to each voltage peak value.

  As shown in FIG. 17, at each voltage, it was found that the maximum flow velocity of the generated airflow was larger when the voltage frequency increased and the discharge input power increased. It was also found that the maximum flow velocity of the generated air flow is larger when the applied voltage is higher even with the same discharge input power. Thus, it was found that the speed of the generated air flow can be controlled by changing the voltage frequency while keeping the voltage peak value constant.

  This control can be performed with a constant applied voltage, and thus is suitable when it is desired to reduce costs by simplifying the insulation design.

(3) Example of control by voltage waveform FIG. 18 is a diagram showing the maximum value of the velocity distribution when the rise time ratio is changed when the voltage peak value and the voltage frequency are constant.

  The airflow generation device used here is the same as the airflow generation device used in the control example using the voltage frequency described above. The method for measuring the velocity of the airflow generated from the airflow generation device is also the same as in the control example using the voltage frequency described above. Here, the voltage frequency is 1 kHz, and the voltage peak value is 4.6 (power 1.6 W), 4.8 (power 1.9 W), 5 (power 2.6 W), 5.2 (power 4 W). It was.

  Here, the rise time ratio refers to the ratio of the applied voltage waveform to the half cycle of the rise time. As shown in FIG. 18, when the rise time is t, the ratio of the rise time t to the half cycle (500 ms). (T / 500).

  As shown in FIG. 18, it was found that the maximum value of the velocity distribution of the air flow changes when the rise time ratio is changed according to each voltage. Thus, it has been found that the velocity of the generated air flow can be controlled by changing the voltage waveform while keeping the voltage peak value and frequency constant. Further, it was found that the rising time ratio is preferably 0.5 or more because the speed of the generated air flow decreases when the rising time ratio of the alternating voltage is small. This control is a preferable method when optimizing the insulation design and noise characteristics of the device.

(4) Example of control by duty ratio FIG. 19 is a diagram showing the maximum value of the velocity distribution when the voltage peak value, the voltage frequency and the voltage waveform are constant and the voltage is intermittently applied to change the duty ratio. is there.

  The airflow generation device used here is the same as the airflow generation device used in the control example using the voltage frequency described above. The method for measuring the velocity of the airflow generated from the airflow generation device is also the same as in the control example using the voltage frequency described above. Here, the voltage peak value was 8 kV and the voltage frequency was 3 kHz. Here, as shown in FIG. 19, the duty ratio refers to the ratio (t1 / t2) of the time t1 during which the voltage is applied to the time t2 of one cycle when the voltage is intermittently applied.

  As shown in FIG. 19, it was found that the maximum flow velocity of the generated air flow can be controlled by changing the duty ratio while keeping the voltage peak value, frequency, and voltage waveform constant. This control is suitable for the case where it is desired to reduce the cost and size of the power source because the voltage peak value, frequency and voltage waveform are controlled to be constant.

(Power supply structure)
FIG. 20 shows a resonance voltage applied to the discharge unit by applying a step voltage to the resonance circuit including the transformer and including the transformer leakage inductance and the capacitance of the discharge unit. It is a figure which shows the current-voltage waveform of discharge when the high voltage power supply of the system which applies is used for the airflow generator which concerns on this invention. In this case, the voltage frequency was 3 kHz, and the discharge input power was 1 W.

  As shown in FIG. 20, it was found that streamer discharge was generated by the waveform of the whisker-like current pulse by using this power source.

(Electrode structure)
Here, as described above, the diameter when the electrode 21 is formed in a rod shape, or the width (the length in the direction in which the airflow is generated) when the electrode 21 is formed in a flat plate shape is expressed as follows. In this case, the reason why 20t or less, and further 2t or less is suitable will be described. The airflow generation device used here differs from the airflow generation device 10 shown in FIG. 14A only in the sizes of electrodes and dielectrics, and the speed measurement method is the same, so the airflow generation used here is the same. The configuration of the device will be described with reference to the airflow generation device 10 in FIG. 14A.

  The airflow generation device 10 uses a stainless steel flat plate or copper foil having a width L1 (length in the airflow generation direction) of 2 mm or 10 mm, a lateral M1 of 110 mm, and a thickness t1 of 0.1 mm as the electrode 21. No. 22 was a stainless steel flat plate or copper foil having a width (length in the direction of air flow generation) of 10 mm, a lateral M2 of 100 mm, and a thickness of 0.1 mm. Between the electrodes, quartz, alumina, and Teflon (registered as a dielectric 20) having a width L3 (length in the direction of air flow) of 120 mm, a width of 120 mm, and a thickness t3 of 0.1 to 3 mm are registered. Trademark) and a flat plate made of polyimide. 14A, the electrode 22 is disposed so that the end surface 22a of the electrode 22 on the airflow generation direction side is flush with the end surface 20a of the dielectric 20 on the airflow generation direction side. On the other hand, the electrode 21 is arranged such that the end surface 21a on the airflow generation direction side of the electrode 21 is located at a position 10 mm away from the end surface 20a of the dielectric 20 in the direction opposite to the airflow generation direction. Further, as shown in FIG. 14A, the wind speed element 141 is located at a position 15 mm downstream from the end face 21 a of the electrode 21 in the air flow generation direction and at the center in the longitudinal direction (lateral M1 direction) of the electrode 22. The hot-wire anemometer 140 was arranged so as to be parallel, and the hot-wire anemometer 140 was moved in the vertical direction (perpendicular to the air flow generation direction), and the velocity distribution in that direction was measured. An alternating voltage having a frequency of 3 kHz and a voltage of 5 kV to 9 kV was applied to the electrodes.

  FIG. 21 is a diagram showing the relationship between the ratio L1 / t3 of the width L1 of the electrode 21 and the thickness t3 of the dielectric 20 and the energy conversion efficiency. Here, the energy conversion efficiency η is obtained by dividing the integral value E obtained by integrating the energy of the airflow in the height direction based on the measured velocity distribution by the discharge input power PW (E / PW). As shown in FIG. 21, it was found that there is a correlation between L1 / t3 and energy conversion efficiency. In the range where the L1 / t3 value in the experiment is 20 or less, a sufficiently usable energy conversion efficiency is obtained. In particular, when the L1 / t3 value is 2 or less, the energy conversion efficiency η increases rapidly. I found out that

(Dielectric structure)
Here, as described above, it will be described that ε / t3 is preferably 20 / mm or less, where t3 is the thickness of the dielectric 20 and ε is the relative dielectric constant. The airflow generation device used here differs from the airflow generation device 10 shown in FIG. 14A only in the sizes of electrodes and dielectrics, and the speed measurement method is the same, so the airflow generation used here is the same. The configuration of the device will be described with reference to the airflow generation device 10 in FIG. 14A.

  The airflow generation device 10 uses a stainless steel flat plate having a width L1 (length in the airflow generation direction) of 2 mm, a lateral M1 of 110 mm, and a thickness t1 of 0.1 mm as the electrode 21, and a width ( A stainless steel flat plate having a length of 10 mm in the airflow generation direction, a lateral M2 of 100 mm, and a thickness of 0.1 mm was used. Between the electrodes, alumina, tempax, quartz, Teflon having a width L3 (length in the direction of air flow) of 120 mm, a width of 120 mm, and a thickness t3 of 0.1 to 3 mm is provided between the electrodes. (Registered trademark), a flat plate made of polyimide was used. 14A, the electrode 22 is disposed so that the end surface 22a of the electrode 22 on the airflow generation direction side is flush with the end surface 20a of the dielectric 20 on the airflow generation direction side. On the other hand, the electrode 21 is arranged such that the end surface 21a on the airflow generation direction side of the electrode 21 is located at a position 10 mm away from the end surface 20a of the dielectric 20 in the direction opposite to the airflow generation direction. Further, as shown in FIG. 14A, the wind speed element 141 is located at a position 15 mm downstream from the end face 21 a of the electrode 21 in the air flow generation direction and at the center in the longitudinal direction (lateral M1 direction) of the electrode 22. The hot-wire anemometer 140 was arranged so as to be parallel, and the hot-wire anemometer 140 was moved in the vertical direction (perpendicular to the air flow generation direction), and the velocity distribution in that direction was measured. An alternating voltage having a frequency of 3 kHz and a voltage of 9 kV was applied to the electrodes.

FIG. 22 is a diagram showing the relationship between the ratio ε / t3 of the relative dielectric constant ε and the thickness t3 of the dielectric 20 and the energy conversion efficiency. Here, the energy conversion efficiency η is obtained by dividing the integral value E obtained by integrating the energy of the airflow in the height direction based on the measured velocity distribution by the discharge input power PW (E / PW). As shown in FIG. 22, it was found that there is a correlation between the ratio ε / t3 of the thickness t3 of the dielectric 20 and the relative dielectric constant ε and the energy conversion efficiency η. And it turned out that energy conversion efficiency (eta) increases rapidly when the value of (epsilon) / t3 is 20 / mm or less.

  Although the present invention has been specifically described above with reference to the embodiments, the present invention is not limited to these embodiments, and various modifications can be made without departing from the scope of the invention.

  DESCRIPTION OF SYMBOLS 10 ... Airflow generator, 20 ... Dielectric, 21,22 ... Electrode, 23 ... Cable, 24 ... Power supply for discharge, 30 ... Streamer for cathode, 31 ... Streamer for anode, 35 ... Airflow.

Claims (10)

An airflow generating unit that generates an airflow by applying a voltage between the first electrode and the second electrode disposed via a solid dielectric and discharging the electrode is provided at a predetermined position on the blade surface, A wing that generates lift,
The dielectric is composed of a block-shaped dielectric block,
The first electrode is provided exposed from one surface of the dielectric block, or embedded in the dielectric block;
The second electrode is shifted from the first electrode in a direction horizontal to the surface of the dielectric block, is separated from the first electrode, and is embedded in the dielectric block ;
A ratio (ε / t) between a relative permittivity ε of the dielectric block and a thickness t (mm) orthogonal to a direction in which an air flow is generated is 20 / mm or less. Wings to do. The ratio of the voltage rise time to the half-cycle time of the alternating voltage applied between the first electrode and the second electrode is 0.5 or more . Wings. In the airflow generation device that generates an airflow by applying a voltage between the first electrode and the second electrode arranged via a solid dielectric and discharging the electrode,
The first electrode is provided exposed from one surface of the dielectric, or embedded in the dielectric;
The second electrode is provided apart from the first electrode by being shifted from the first electrode in a direction horizontal to the surface of the dielectric, and exposed from the other surface of the dielectric; or Embedded in the dielectric,
The ratio of the relative dielectric constant ε of the dielectric to the thickness t (mm) perpendicular to the direction in which the airflow is generated (ε / t) is 20 / mm or less. Generator. The ratio (L / t) between the width L of the first electrode in the direction of generating an air flow and the thickness t of the dielectric perpendicular to the direction of generating the air flow is 2 or less. The airflow generation device according to claim 3 . An airflow generator that generates an airflow by applying a voltage between a first electrode and a second electrode that are disposed via a solid dielectric and discharging them to transfer heat to a working fluid gas. A heat exchange device provided at a predetermined position on the heat transfer surface,
The first electrode is provided exposed from one surface of the dielectric, or embedded in the dielectric;
The second electrode is provided apart from the first electrode by being shifted from the first electrode in a direction horizontal to the surface of the dielectric, and exposed from the other surface of the dielectric; or Embedded in the dielectric ,
The ratio (ε / t) between the relative dielectric constant ε of the dielectric and the thickness t (mm) perpendicular to the direction in which the air flow is generated is 20 / mm or less. Exchange device. An airflow generating device that generates an airflow by applying a voltage between a first electrode and a second electrode arranged via a solid dielectric and discharging the electrode is used as a driving mechanism at a predetermined position on the surface. A micromachine that can move in any direction,
The first electrode is provided exposed from one surface of the dielectric, or embedded in the dielectric;
The second electrode is provided apart from the first electrode by being shifted from the first electrode in a direction horizontal to the surface of the dielectric, and exposed from the other surface of the dielectric; or Embedded in the dielectric ,
A ratio (ε / t) between a relative dielectric constant ε of the dielectric and a thickness t (mm) perpendicular to a direction in which an air flow is generated is 20 / mm or less. . An active species generating mechanism for generating active species by discharge, a gas processing mechanism for processing a gas to be treated, and a blowing mechanism for blowing the active species generated by the active species generating mechanism to the gas processing mechanism;
Both the active species generating mechanism and the air blowing mechanism are provided in an active species generating unit that generates active species, and a first electrode and a second electrode disposed via a solid dielectric A gas treatment device composed of an airflow generation device that generates an airflow by applying a voltage during discharge to discharge,
The first electrode is provided exposed from one surface of the dielectric, or embedded in the dielectric;
The second electrode is provided apart from the first electrode by being shifted from the first electrode in a direction horizontal to the surface of the dielectric, and exposed from the other surface of the dielectric; or Embedded in the dielectric ,
A gas characterized in that a ratio (ε / t) of a relative dielectric constant ε of the dielectric and a thickness t (mm) orthogonal to a direction in which an air flow is generated is 20 / mm or less. Processing equipment.   The ratio (L / t) between the width L of the first electrode in the direction of generating an air flow and the thickness t of the dielectric perpendicular to the direction of generating the air flow is 2 or less. The heat exchange device according to claim 5.   The ratio (L / t) between the width L of the first electrode in the direction of generating an air flow and the thickness t of the dielectric perpendicular to the direction of generating the air flow is 2 or less. The micromachine according to claim 6.   The ratio (L / t) between the width L of the first electrode in the direction of generating an air flow and the thickness t of the dielectric perpendicular to the direction of generating the air flow is 2 or less. The gas processing apparatus according to claim 7.