CN115610648A - Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter - Google Patents
Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/32—Rotors
- B64C27/46—Blades
- B64C27/467—Aerodynamic features
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/04—Helicopters
- B64C27/06—Helicopters with single rotor
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/04—Helicopters
- B64C27/08—Helicopters with two or more rotors
- B64C27/10—Helicopters with two or more rotors arranged coaxially
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Abstract
The invention provides a variable-speed rotor blade, a coaxial unmanned helicopter and a single-rotor unmanned helicopter, wherein the variable-speed rotor blade comprises: the oar root that connects gradually, paddle middle section and oar point, the pitch curve L of variable rotational speed rotor blade includes root pitch section L1, middle part pitch section L2 and the pitch section L3 of point portion that corresponds with the oar root respectively, paddle middle section and oar point, regard as standard pitch L4 with the pitch that the tie point of middle part pitch section L2 and point portion pitch section L3 corresponds, the pitch that each point in the pitch section L3 of point portion corresponds all is less than standard pitch L4. By applying the technical scheme of the invention, the tip part of the variable-speed rotor blade has larger negative torsion and smaller phyllotactic incidence angle, so that the tip part can generate larger change of lift coefficient in the process of periodic variable pitch, thereby improving the control capability of the periodic variable pitch.
Description
Technical Field
The invention relates to the field of aircrafts, in particular to a variable-speed rotor blade, a coaxial unmanned helicopter and a single-rotor unmanned helicopter.
Background
The coaxial helicopter has the advantages of small size, no tail rotor, high hovering efficiency and the like, and is an unmanned helicopter layout mode most suitable for light and miniaturized development. Light-duty and miniature coaxial unmanned aerial vehicle no matter in civilian, for military use aspect, its portability has certain advantage relatively many rotor unmanned aerial vehicle.
However, the variable-speed rotor blades of the light and miniature coaxial unmanned aerial vehicles in the prior art have weak control torque under the action of only periodic variable pitch.
Disclosure of Invention
The invention mainly aims to provide a variable-speed rotor blade, a coaxial unmanned helicopter and a single-rotor unmanned helicopter, and aims to solve the problem that the variable-speed rotor blade in the prior art has weak control torque under the action of only periodic variable pitch.
To achieve the above object, according to one aspect of the present invention, there is provided a variable speed rotor blade comprising: the oar root that connects gradually, paddle middle section and oar point, the pitch curve L of variable rotational speed rotor blade includes root pitch section L1, middle part pitch section L2 and the pitch section L3 of point portion that corresponds with the oar root respectively, paddle middle section and oar point, regard as standard pitch L4 with the pitch that the tie point of middle part pitch section L2 and point portion pitch section L3 corresponds, the pitch that each point in the pitch section L3 of point portion corresponds all is less than standard pitch L4.
In one embodiment, the tip corresponding to the outermost side of the tip has a maximum negative torque c, the maximum negative torque c is the difference between the pitch of the tip corresponding to the outermost side of the tip and the standard pitch L4, and the maximum negative torque c is between 1.6inch and 2.2 inch.
In one embodiment, the tip pitch segment L3 includes a first straight line segment L5, the slope of the first straight line segment L5 is between-10 and-20, and the pitch corresponding to the end of the first straight line segment L5 is the pitch of the tip corresponding to the outermost side of the tip.
In one embodiment, the tip pitch segment L3 further includes a first arc transition segment L6 connected between the end of the middle pitch segment L2 and the start of the first straight segment L5.
In one embodiment, each point within the middle pitch segment L2 corresponds to a pitch that is greater than the standard pitch L4.
In one embodiment, the connecting point of the blade root and the blade middle section has the maximum positive torsion d, the maximum positive torsion d is the difference between the screw pitch corresponding to the connecting point of the blade root and the blade middle section and the standard screw pitch L4, and the maximum positive torsion d is between 0.2inch and 1.1 inch.
In one embodiment, the middle pitch segment L2 includes a second straight line segment L7, a slope of the second straight line segment L7 is less than 0 and equal to or greater than-0.9, a pitch corresponding to a tail end of the second straight line segment L7 is a standard pitch L4, and a difference between a pitch corresponding to a start end of the second straight line segment L7 and the standard pitch L4 is between 0.15 and 0.25.
In one embodiment, the middle pitch segment L2 further comprises a second arc transition segment L8 connected between the end of the root pitch segment L1 and the beginning of the second straight segment L7.
In one embodiment, the overhang amount e is the portion of the variable speed rotor blade with the relative radius between 0 and 0.27, the portion of the variable speed rotor blade with the relative radius between 0.27 and 0.4 corresponds to the root, the portion of the variable speed rotor blade with the relative radius between 0.4 and 0.75 corresponds to the midspan, and the portion of the variable speed rotor blade with the relative radius between 0.75 and 1 corresponds to the tip.
In one embodiment, the maximum value of the angle of attack of the phyllotaxis of the root is between 16 ° and 25 °.
In one embodiment, the pitch axis L9 of the variable speed rotor blade is between the first 35% and 47% of the mean chord length of the variable speed rotor blade.
In one embodiment, the variable speed rotor blade has an airfoil profile with a Reynolds number of 10 or less 6 An airfoil of (a).
In one embodiment, the projection of the variable-speed rotor blade in a reference plane is taken as a blade plane shape, the front edge of the blade plane shape comprises a blade root front edge projection, a middle section front edge projection and a blade tip front edge projection which correspond to a blade root, a blade middle section and a blade tip respectively, the rear edge of the blade plane shape comprises a blade root rear edge projection, a middle section rear edge projection and a blade tip rear edge projection which correspond to the blade root, the blade middle section and the blade tip respectively, the blade root front edge projection and the blade root rear edge projection are parallel to a variable pitch axis L9, the middle section front edge projection and the blade tip front edge projection are swept backward, the middle section rear edge projection and the blade tip rear edge projection are swept forward, and the sweep angle of the blade tip rear edge projection is smaller than that of the middle section rear edge projection.
In one embodiment, the projection of the front edge of the blade tip comprises a third straight line segment and a third circular arc transition segment which are sequentially connected in the direction from the blade root to the blade tip.
According to another aspect of the present invention, there is provided a coaxial unmanned helicopter comprising: the variable-speed rotor blade is the variable-speed rotor blade.
In one embodiment, the rotor solidity of the coaxial drone ranges between 0.98 and 1.1.
According to a final aspect of the present invention, there is provided a single-rotor unmanned helicopter comprising: the variable-speed rotor blade is the variable-speed rotor blade.
In one embodiment, the rotor solidity of the single-rotor unmanned helicopter ranges from 0.49 to 0.55.
By applying the technical scheme of the invention, the pitches corresponding to all points in the pitch section L3 of the tip part are smaller than the standard pitch L4, namely the tip part of the rotating speed variable rotor blade has larger negative torsion and smaller phyllotaxis incidence angle, so that the tip part can generate larger change of lift coefficient, namely larger lift difference in the process of periodic variable pitch. Such a lift difference provides a cyclic moment of the forward flight of the aircraft, so that a larger lift difference can improve the cyclic handling capability.
In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 shows a schematic perspective view of an embodiment of a variable speed rotor blade according to the present invention, wherein fig. 1 shows the phyllines at different radii;
FIG. 2 illustrates a blade planform of the variable speed rotor blade of FIG. 1;
FIG. 3 illustrates a blade planform of the variable speed rotor blade of FIG. 1;
FIG. 4 shows a schematic view of a pitch curve L of the variable speed rotor blade of FIG. 1;
FIG. 5 illustrates a pitch profile of the variable speed rotor blade of FIG. 1 after transformation of a coordinate system;
FIG. 6 is a graph illustrating lift coefficients for an airfoil of the variable speed rotor blade of FIG. 1 and other low Reynolds number airfoils;
FIG. 7 illustrates pole plots for an airfoil of the variable speed rotor blade of FIG. 1 and other low Reynolds number airfoils;
FIG. 8 illustrates an example rotor chord length distribution plot for the variable speed rotor blade of FIG. 1;
FIG. 9 is a graph illustrating a slip-flow vertical component profile 0.65R downstream of a rotor blade disk of the variable speed rotor blade of FIG. 1;
FIG. 10 illustrates a graph of the stagger angle of the variable speed rotor blade of FIG. 1; and
fig. 11 shows a flow chart of the design of the variable speed rotor blade of fig. 1.
Wherein the figures include the following reference numerals:
10. a paddle root; 11. propeller root leading edge projection; 12. the rear edge projection of the paddle root; 20. a blade middle section; 21. projecting the front edge of the middle section; 22. projecting the rear edge of the middle section; 30. a blade tip; 31. projecting the front edge of the blade tip; 311. a third straight line segment; 312. a third arc transition section; 32. the rear edge projection of the blade tip.
Detailed Description
It should be noted that the embodiments and features of the embodiments of the present invention may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances for describing embodiments of the invention described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
In order to solve the above problem, as shown in fig. 1, 4 and 5, the variable speed rotor blade of the present embodiment includes: the oar root 10 that connects gradually, paddle middle section 20 and oar point 30, the pitch curve L of variable rotational speed rotor blade include respectively with the oar root 10, the root pitch section L1 that paddle middle section 20 and oar point 30 correspond, middle part pitch section L2 and sharp portion pitch section L3, the pitch that the tie point with middle part pitch section L2 and sharp portion pitch section L3 corresponds is as standard pitch L4, the pitch that each point in the sharp portion pitch section L3 corresponds all is less than standard pitch L4.
By applying the technical scheme of the embodiment, the pitches corresponding to all points in the pitch section L3 of the tip part are smaller than the standard pitch L4, that is to say, the tip part of the rotor blade with variable rotation speed has larger negative torsion and smaller leaflet attack angle, so that the tip part can generate larger change of lift coefficient, namely larger lift difference in the process of periodic pitch variation. Such a lift difference provides a cyclic moment of forward flight of the aircraft, so a larger lift difference can improve the cyclic handling capability.
As shown in fig. 4, in the present embodiment, the tip portion corresponding to the outermost side of the tip 30 has the maximum negative torsion amount c, which is the difference between the pitch of the tip portion corresponding to the outermost side of the tip 30 and the standard pitch L4, and the maximum negative torsion amount c is between 1.6inch and 2.2 inch. If the maximum negative torsion c is too small, the lift difference is not obviously improved, and the improvement on the control capability of the periodic variable pitch is limited. Whereas blade efficiency is lost if the maximum negative torque c is too large. Preferably, in the present embodiment, the maximum negative torsion amount c is 2inch.
As shown in fig. 4, in the present embodiment, the tip pitch segment L3 includes a first straight line segment L5, the slope of the first straight line segment L5 is between-10 and-20 (i.e. linear negative twist), and the pitch corresponding to the end of the first straight line segment L5 is the pitch of the tip corresponding to the outermost side of the blade tip 30. The structure enables the slope of the first straight line segment L5 to be larger, so that the incidence angle of the chlorophyll is smaller, the lift difference is further increased, and the control capacity of the periodic variable pitch is improved. It should be noted that too small a slope of the first straight line L5 affects the ability of the cyclic pitch control, and too large a slope of the first straight line L5 results in loss of blade efficiency.
Preferably, in the present embodiment, the slope of the first straight line segment L5 is-14.2. When the lutein incidence angle is adjusted, only the maximum negative torsion amount c or only the slope of the first straight line segment L5 may be adjusted, or the maximum negative torsion amount c and the first straight line segment L5 may be adjusted in a combined manner. In contrast, the maximum negative twist c has a greater effect on the angle of attack of the phyllotaxis.
As shown in fig. 4, in the present embodiment, the tip pitch segment L3 further includes a first arc transition segment L6 connected between the end of the middle pitch segment L2 and the start of the first straight line segment L5. The structure prevents the incidence angle of the phyllotoxin from sudden change, and is favorable for subsequent lofting modeling.
As shown in fig. 4, in the present embodiment, the pitch of each point in the middle pitch segment L2 is greater than the standard pitch L4, i.e. the middle blade segment 20 is positively twisted. Specifically, the closer to the root 10, the larger the pitch. At a given speed, the linear velocity is smaller closer to the root 10 and greater closer to the tip 30. Since the linear speed of the position of the propeller root 10 is small, and the lift force is insufficient, positive torsion is added in the middle pitch section L2 connected with the propeller root 10, so that the attack angle is increased, and the lift force is improved.
As shown in fig. 4, in the present embodiment, the connection point of the root 10 and the blade middle section 20 has a maximum positive torsion amount d, the maximum positive torsion amount d is a difference between a pitch corresponding to the connection point of the root 10 and the blade middle section 20 and a standard pitch L4, and the maximum positive torsion amount d is between 0.2inch and 1.1 inch. If the maximum positive torsion d is too small, the increase of the angle of attack of the lutein is not obvious, so that the lift force lifting effect is not obvious, and if the maximum positive torsion d is too large, the resistance of the part of the oar root 10 is increased, so that the oar root 10 stalls. Preferably, in the present embodiment, the maximum positive torsion amount d is 1inch.
In this embodiment, the root of the blade root 10 is in transition form to the maximum pitch.
It is also noted that as shown in fig. 2, 4 and 9, the root 10 and mid-blade section 20 are twisting, so that the distribution of the vertical component of the slip stream downstream of the blade disk from the root to 80% of the relative radius (R/R) is relatively uniform, thereby improving the efficiency of hover and low speed forward flight. Note that R is a distance from the rotation center O to the tip of the tip 30. The axis of the rotation center O is a rotation shaft Q.
As shown in fig. 4, in the present embodiment, the middle pitch segment L2 includes a second straight line segment L7, a slope of the second straight line segment L7 is smaller than 0 and greater than or equal to-0.9 (i.e., linear negative twist), a pitch corresponding to a tail end of the second straight line segment L7 is a standard pitch L4, and a difference between a pitch corresponding to a start end of the second straight line segment L7 and the standard pitch L4 is between 0.15 and 0.25. The structure enables the second straight-line section L7 to be close to the standard pitch L4 as much as possible, so that the variable-speed advantage of the standard pitch propeller is effectively inherited. Preferably, the endpoint for L7 differs from L4 by 0.2.
As shown in fig. 4, in the present embodiment, the middle pitch segment L2 further includes a second arc transition segment L8 connected between the end of the root pitch segment L1 and the start end of the second straight line segment L7. The structure prevents the incidence angle of the phyllotoxin from sudden change, and is favorable for subsequent lofting modeling.
It should be noted that the variable speed rotor blade has a nonlinear negative twist as a whole. But the overall size is smaller, the manufacturing difficulty is low by using a composite material mould pressing process, and the manufacturing is easy.
As shown in fig. 2 to 4, in the present embodiment, the portion of the variable-speed rotor blade having a relative radius between 0 and 0.27 is the overhang amount e, the portion of the variable-speed rotor blade having a relative radius between 0.27 and 0.4 corresponds to the root 10, the portion of the variable-speed rotor blade having a relative radius between 0.4 and 0.75 corresponds to the blade center section 20, and the portion of the variable-speed rotor blade having a relative radius between 0.75 and 1 corresponds to the tip 30. As shown in fig. 10, the mount angle at the tip 30 portion varies from 7.7 to 2.8 degrees from the relative radius of 0.75 to the outermost side. If the rotor is subjected to +/-10-degree periodic pitch change. The blade angle of attack of the tip 30 is in the range of-7.2 to 17.7. As can be seen from fig. 6, during one period of pitch variation, the blade tip portion generates a large lift coefficient change, i.e., a large lift difference. Such lift difference provides a cyclic moment of forward flight of the rotorcraft.
Note that, as shown in fig. 2, the overhang amount e is the distance between the center of rotation O and the vertical hinge P of the variable speed rotor blade.
And also need to be explainedFIG. 10 is a graph illustrating a variable speed rotor blade setting angle curve that can be expressed by the pitch curve L of FIG. 4 and the equation
Obtaining the relative radius of the position where each phylline is located is r 1 Where the pitch is a 1 Where the mounting angle is alpha. And (4) calculating a blade phylline installation angle curve through the pitch curve L, and then performing lofting drawing.
In the present embodiment, the maximum value of the angle of attack of the phyllotaxis of the root 10 is between 16 ° and 25 °. Too little leaflet angle of attack results in insufficient lift and too great leaflet angle of attack results in increased drag on the root 10, resulting in stall. Preferably, in the present embodiment, the place where the leaflet angle of attack is largest is not necessarily the place of maximum pitch. The maximum value of the phyllotactic angle of attack is 18.5 ° at the relative radius R/R = 0.35.
As shown in fig. 2, in the present embodiment, the pitch axis L9 of the variable speed rotor blade is between the first 35% and 47% of the mean chord length of the variable speed rotor blade. Note that the above description means that, in the direction from the leading edge to the trailing edge of the variable speed rotor blade, the variable pitch axis L9 is perpendicular to the chord length and passes through a point within the first 35% to 47% of the average chord length of the variable speed rotor blade as a reference point. The above structure makes the pitch axis L9 near the aerodynamic center, so that the torque generated around the pitch axis L9 during the pitch is small, thereby reducing the load on the pitch mechanism. Preferably, in this embodiment, the pitch axis L9 of the blade is at the first 46% of the mean chord length.
The inventor finds that the main reason that the endurance of the light and micro coaxial unmanned aerial vehicles is insufficient after long-term research is that the rotor blades mainly adopt model-level blades, the wing type mainly adopts symmetrical wing types, and the hovering efficiency is low due to the fact that the wing type is not optimally designed. It is not suitable for variable speed control.
To solve the above problem, in this embodiment, the profile of the variable speed rotor blade has a reynolds number of 10 or less 6 An airfoil of (a). Preferably, in this embodiment, the variable speed rotor blade has an airfoil profile of NACA3412. When in useHowever, in other embodiments, the airfoil of the variable speed rotor blade may be an airfoil with a low reynolds number, such as Eppler387 or a 18. The following describes in detail the method of selection of the airfoil:
when the wing profile is selected, the lift coefficient curve and the polar curve of several target wing profiles are compared. First, the lift coefficient should have a large angle of attack at the maximum lift coefficient. As shown in fig. 6 (lift curve), the angle of attack of the NACA3412 airfoil at maximum lift coefficient is greater than the other two airfoils. Secondly, the polar curve should have a larger opening, i.e. a larger range of variation of the lift coefficient at a smaller drag coefficient. As shown in fig. 7 (polar curve), the polar curve of the NACA3412 airfoil has larger openings. Thus, the present embodiment selects the NACA3412 airfoil as the airfoil for the variable speed rotor blade.
As shown in fig. 2 and 3, in the present embodiment, the projection of the variable-speed rotor blade in the reference plane is taken as the blade plane shape, the front edge of the blade plane shape includes a blade root front edge projection 11, a middle section front edge projection 21 and a blade tip front edge projection 31 corresponding to the blade root 10, the blade middle section 20 and the blade tip 30, respectively, the rear edge of the blade plane shape includes a blade root rear edge projection 12, a middle section rear edge projection 22 and a blade tip rear edge projection 32 corresponding to the blade root 10, the blade middle section 20 and the blade tip 30, respectively, the blade root front edge projection 11, the blade root rear edge projection 12 are parallel to the variable-pitch axis L9, the middle section front edge projection 21 and the blade tip front edge projection 31 are swept back, the middle section rear edge projection 22 and the blade tip rear edge projection 32 are swept forward, and the sweep angle of the blade tip rear edge projection 32 is smaller than that of the middle section rear edge projection 22. Under the combined action of the special blade plane shape and the corresponding pitch curve, the difference of the vertical components of the slip flow at the downstream of the paddle disk can be reduced, so that the distribution of the vertical components of the slip flow at the downstream of the paddle disk from the paddle root to the position with the relative radius (R/R) of 80% is relatively uniform, and the hovering and low-speed forward flying efficiency is improved.
It should be noted that, as shown in fig. 8, the chord length of the blade decreases gradually from the root 10 to the tip 30, which helps to reduce rotor drag and tip loss.
As shown in fig. 3, in the present embodiment, the tip leading edge projection 31 includes a third straight line segment 311 and a third arc transition segment 312, which are sequentially connected in the direction from the blade root 10 to the blade tip 30. The structure enables the chord length of the variable-speed rotor blade to be reduced on one hand, so that the resistance is reduced; and on the other hand, the noise reduction function is realized.
Fig. 11 shows a flow chart of the design of the variable speed rotor blade of the present embodiment.
The present application further provides a coaxial unmanned helicopter, an embodiment of a coaxial unmanned helicopter (not shown in the figures) according to the present application comprises a variable speed rotor blade as described above. The coaxial unmanned helicopter with the variable-speed rotor blade has the advantages because the variable-speed rotor blade has stronger control moment under the action of only periodic variable pitch.
In this embodiment, the rotor solidity of the coaxial unmanned helicopter ranges from 0.98 to 1.1. Specifically, the solidity is the ratio of the vertical projection area of one pair of blades to the area of the paddle disk, and the solidity is in the range, so that the rotor wing of the coaxial unmanned helicopter has the highest efficiency and the longest endurance time.
The application also provides a single-rotor unmanned helicopter, and an embodiment of the single-rotor unmanned helicopter (not shown in the figure) according to the application comprises variable-speed rotor blades, and the variable-speed rotor blades are the variable-speed rotor blades. Because the variable-speed rotor blade has stronger control moment under the action of only periodic variable pitch, the single-rotor unmanned helicopter with the variable-speed rotor blade also has the advantages.
In the embodiment, the rotor solidity of the single-rotor unmanned helicopter ranges from 0.49 to 0.55. The solidity is in the range, so that the rotor efficiency of the single-rotor unmanned helicopter is highest, and the endurance time is longest.
The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as exemplary only and not as limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
For ease of description, spatially relative terms such as "over 8230 \ 8230;,"' over 8230;, \8230; upper surface "," above ", etc. may be used herein to describe the spatial relationship of one device or feature to another device or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary terms "at 8230; \8230; 'above" may include both orientations "at 8230; \8230;' above 8230; 'at 8230;' below 8230;" above ". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
In the description of the present invention, it is to be understood that the directions or positional relationships indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the directions or positional relationships shown in the drawings, and are for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (18)
1. A variable speed rotor blade, comprising: the oar root (10), paddle middle section (20) and oar point (30) that connect gradually, the pitch curve L of variable rotational speed rotor blade include respectively with oar root (10), paddle middle section (20) and root pitch section L1, middle part pitch section L2 and sharp portion pitch section L3 that oar point (30) correspond, with middle part pitch section L2 with the pitch that the tie point of sharp portion pitch section L3 corresponds is as standard pitch L4, the pitch that each point in the sharp portion pitch section L3 corresponds all is less than standard pitch L4.
2. The variable speed rotor blade according to claim 1, wherein the tip corresponding to the outermost side of the tip (30) has a maximum negative torque c, which is the difference between the pitch of the tip corresponding to the outermost side of the tip (30) and a standard pitch L4, the maximum negative torque c being between 1.6inch and 2.2 inch.
3. The variable speed rotor blade according to claim 1, wherein the tip pitch segment L3 comprises a first straight line segment L5, the slope of the first straight line segment L5 is between-10 and-20, and the tip of the first straight line segment L5 corresponds to a pitch of the tip corresponding to the outermost side of the tip (30).
4. The variable speed rotor blade according to claim 3 wherein the tip pitch section L3 further comprises a first arc transition section L6 connected between the end of the middle pitch section L2 and the beginning of the first straight section L5.
5. The variable speed rotor blade according to claim 1 wherein each point in the intermediate pitch section L2 corresponds to a pitch that is greater than the nominal pitch L4.
6. The variable speed rotor blade according to claim 5, wherein the connection point of the root (10) and the mid-blade (20) has a maximum positive torque d, which is the difference between the pitch corresponding to the connection point of the root (10) and the mid-blade (20) and the standard pitch L4, said maximum positive torque d being between 0.2inch and 1.1 inch.
7. The variable speed rotor blade according to claim 5 wherein the middle pitch segment L2 comprises a second straight line segment L7, the slope of the second straight line segment L7 is less than 0 and equal to or greater than-0.9, the pitch corresponding to the end of the second straight line segment L7 is the standard pitch L4, and the difference between the pitch corresponding to the start of the second straight line segment L7 and the standard pitch L4 is between 0.15 and 0.25.
8. The variable speed rotor blade according to claim 7 wherein the middle pitch section L2 further comprises a second arc transition section L8 connected between the end of the root pitch section L1 and the beginning of the second straight section L7.
9. The variable speed rotor blade according to claim 1, wherein the portion of the variable speed rotor blade having a relative radius between 0 and 0.27 is the overhang e, the portion of the variable speed rotor blade having a relative radius between 0.27 and 0.4 corresponds to the root (10), the portion of the variable speed rotor blade having a relative radius between 0.4 and 0.75 corresponds to the blade midsection (20), and the portion of the variable speed rotor blade having a relative radius between 0.75 and 1 corresponds to the tip (30).
10. Variable speed rotor blade according to claim 1, wherein the maximum value of the angle of attack of the leaflets of the root (10) is between 16 ° and 25 °.
11. A variable speed rotor blade according to claim 1 wherein the variable speed rotor blade pitch axis L9 is between the first 35% and 47% of the mean chord length of the variable speed rotor blade.
12. The variable speed rotor blade according to claim 1 wherein the variable speed rotor blade has an airfoil profile with a reynolds number of 10 or less 6 The airfoil of (1).
13. The variable speed rotor blade according to any of claims 1-12 wherein the variable speed rotor blade projection in a reference plane is taken as a blade planform, the blade planform leading edge comprises a blade root leading edge projection (11), a midspan leading edge projection (21) and a tip leading edge projection (31) corresponding to the blade root (10), blade midspan (20) and tip (30), respectively, and the blade planform trailing edge comprises a blade root trailing edge projection (12), a midspan trailing edge projection (22) and a tip trailing edge projection (32) corresponding to the blade root (10), blade midspan (20) and tip (30), respectively, the blade root leading edge projection (11), the blade root trailing edge projection (12) being parallel to the variable pitch axis L9, the midspan projection (21) and the tip leading edge projection (31) being swept, the midspan projection (22) and the tip trailing edge projection (32) being swept forward, the tip trailing edge projection (32) being swept forward at a sweep angle less than the midspan projection (22).
14. The variable speed rotor blade according to claim 13, wherein the tip leading edge projection (31) comprises a third straight line segment (311) and a third circular arc transition segment (312) connected in series in a direction from the root (10) to the tip (30).
15. A coaxial unmanned helicopter comprising: variable speed rotor blade, characterized in that it is a variable speed rotor blade according to any one of claims 1 to 14.
16. The coaxial drone of claim 15, wherein the coaxial drone has a rotor solidity ranging between 0.98 and 1.1.
17. A single-rotor unmanned helicopter comprising: variable speed rotor blade, characterized in that it is a variable speed rotor blade according to any one of claims 1 to 14.
18. The single-rotor unmanned helicopter of claim 17, wherein the rotor solidity of the single-rotor unmanned helicopter is in a range of between 0.49 and 0.55.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211358567.7A CN115610648A (en) | 2022-11-01 | 2022-11-01 | Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter |
| PCT/CN2023/115622 WO2024093481A1 (en) | 2022-11-01 | 2023-08-29 | Variable-rotating-speed rotor blade, coaxial unmanned helicopter, and single-rotor unmanned helicopter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211358567.7A CN115610648A (en) | 2022-11-01 | 2022-11-01 | Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter |
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| CN115610648A true CN115610648A (en) | 2023-01-17 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202211358567.7A Pending CN115610648A (en) | 2022-11-01 | 2022-11-01 | Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter |
Country Status (2)
| Country | Link |
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| CN (1) | CN115610648A (en) |
| WO (1) | WO2024093481A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024093481A1 (en) * | 2022-11-01 | 2024-05-10 | 苏州览众科技有限公司 | Variable-rotating-speed rotor blade, coaxial unmanned helicopter, and single-rotor unmanned helicopter |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118246157B (en) * | 2024-05-29 | 2024-08-23 | 中国人民解放军陆军指挥学院 | Three-dimensional blade design method of rotor unmanned aerial vehicle |
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| CN207631487U (en) * | 2017-12-21 | 2018-07-20 | 深圳市大疆创新科技有限公司 | Propeller, Power Component and unmanned vehicle |
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| CN115610648A (en) * | 2022-11-01 | 2023-01-17 | 苏州览众科技有限公司 | Variable-speed rotor blade, coaxial unmanned helicopter and single-rotor unmanned helicopter |
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| WO2024093481A1 (en) * | 2022-11-01 | 2024-05-10 | 苏州览众科技有限公司 | Variable-rotating-speed rotor blade, coaxial unmanned helicopter, and single-rotor unmanned helicopter |
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| Publication number | Publication date |
|---|---|
| WO2024093481A1 (en) | 2024-05-10 |
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