CN211370561U - Air inlet channel - Google Patents

Abstract

The utility model discloses an air intake channel for an engine, which comprises a blunt leading edge, wherein the blunt leading edge comprises a smooth transition section located in the center and a straight section connected with both ends of the smooth transition section; The air inlet and the air outlet are connected through the guide channel at the position of the blunt leading edge, and the distance between the air inlet and the center of the smooth transition section is smaller than that between the air outlet and the smooth transition section distance from the center. In the blunt leading edge provided by the present application, by opening a diversion channel on the blunt leading edge and utilizing the static pressure difference between the upstream and downstream of the flow field, the flow self-circulation can be realized without additional power device and energy supply system, and the structure is simple. It is easy to implement, directing the airflow at the high pressure to the low pressure position, reducing the distance from the shock wave at the center of the smooth transition section to the wall surface, effectively reducing the wall pressure and heat flow load peak of the blunt leading edge, thereby improving the performance of the intake port.

Description

an air intake

technical field

The utility model relates to the technical field of high Mach number pneumatics, in particular to an air inlet.

Background technique

High Mach number aircraft has extremely important military and civilian value. Scramjet is one of the most potential power methods to achieve this high-speed flight. As an important part of scramjet, its performance is directly related to its performance. Efficiency of the entire propulsion system. In recent years, the internally rotating intake port using the combination of curved shock wave and isentropic compression has received extensive attention due to its excellent performance such as high airflow compression rate and low total pressure loss.

However, due to the highly swept-back of the leading edge of the inner-turn intake port, the intersection of the root of the leading edge forms a V-shaped overflow port. In the actual design, for the consideration of aerodynamic thermal protection and structural strength, it is necessary to do a certain degree of passivation treatment on the leading edge of the intake port exposed to the incoming flow of high Mach number. However, after the leading edge of the intake port is passivated, the shock wave is no longer attached to the body, and the appearance of the off-body shock wave leads to a complex wave structure near the overflow, and may cause the wall pressure, heat flow increase and unsteady oscillation of the flow. , which not only brings severe challenges to the structural strength of the intake port overflow, but also affects the performance of the intake port.

Therefore, how to improve the performance of the engine intake port is a technical problem to be solved urgently by those skilled in the art.

Utility model content

The purpose of the utility model is to provide an air inlet to improve the performance of the air inlet.

In order to achieve the above purpose, the present invention provides an air intake port for an engine, comprising a blunt leading edge, the blunt leading edge includes a smooth transition section at the center and a straight section connected with both ends of the smooth transition section. ;

The blunt front edge is provided with an air inlet and an air outlet, the air inlet and the air outlet are connected through a guide channel at the position of the blunt front edge, and the air inlet is connected to the center of the smooth transition section. The distance is smaller than the distance between the air outlet and the center of the smooth transition section.

Preferably, there are two diversion channels, and the two diversion channels are respectively arranged on opposite sides of the centerline of the blunt leading edge.

Preferably, the two air guide passages share one air inlet, and the air inlet is located at the center of the smooth transition section.

Preferably, the centerline of the smooth transition section is a circular arc structure.

Preferably, the air inlet, the air outlet and the guide channel are all pipes with circular cross-sections.

Preferably, the diameter D ₁ of the air inlet satisfies:

0.3r≤D ₁ ≤0.4r;

The two air outlets are distributed on opposite sides of the center line of the blunt front edge, and are symmetrically distributed, the air outlet and the diversion channel are equal-section pipes, and the air outlet and the diversion channel are equal. The diameter D ₂ satisfies:

where r is the passivation radius of the blunt leading edge.

Preferably, the air outlet is located at the junction of the straight section and the smooth transition section, and the horizontal distance L1 between the center _of the air outlet and the center of the smooth transition section satisfies:

0.2r≤L ₁ ≤8r.

Preferably, the connection between the air inlet and the diversion channel is connected by a variable-section circular pipe;

The horizontal distance L ₂ between the center of the air inlet and the starting point of the connection of the diversion channel satisfies:

0.3r≤L ₂ ≤1r;

where r is the passivation radius of the blunt leading edge.

Preferably, the guide channel and the air inlet and the air outlet are all rounded and smoothly transitioned;

The rounding radius R ₁ of the transition between the air inlet and the diversion channel satisfies:

0.2r≤R ₁ ≤1r;

where r is the passivation radius of the blunt leading edge.

Preferably, the rounding radius R ₂ of the transition between the air outlet and the diversion channel satisfies:

0.5r≤R ₂ ≤4r.

In the above technical solution, the air inlet provided by the present invention, which is used in an engine, includes a blunt leading edge, and the blunt leading edge includes a smooth transition section at the center and a straight section connected to both ends of the smooth transition section. The blunt leading edge is provided with an air inlet and an air outlet. The air inlet and the air outlet are connected by a guide channel at the position of the blunt leading edge. The distance between the air inlet and the center of the smooth transition section is smaller than the distance between the air outlet and the center of the smooth transition section. . When the engine is working, near the center of the smooth transition section, the shock wave interference is complex and the pressure is high; in the upstream of the smooth transition section, the pressure is low; using the static pressure difference between the upstream and downstream of the flow field, the high pressure at the center of the smooth transition section is reduced. The airflow is drawn away from the air inlet, and is re-ejected at the air outlet where the upstream pressure is lower through the diversion channel, realizing a self-circulating flow control loop.

It can be seen from the above description that, in the intake port provided by the present application, by opening a guide channel on the blunt leading edge, the flow self-circulation can be realized by using the static pressure difference between the upstream and downstream of the flow field without additional power devices and energy supply systems. , the structure is simple, the realization is easy, the air flow at the high pressure is directed to the low pressure position, the distance from the shock wave at the center of the smooth transition section to the wall surface is reduced, the wall pressure and heat flow load peak of the blunt leading edge wall are effectively reduced, and the performance of the intake port is improved.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description It is only an embodiment of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative efforts.

1 is an axonometric view of a blunt leading edge provided by an embodiment of the present invention;

2 is a spanwise cross-sectional view of a blunt leading edge provided by an embodiment of the present invention;

Fig. 3 is the enlarged view of A part shown in Fig. 2;

Fig. 4 is the blunt leading edge provided by the utility model and the traditional blunt leading edge symmetry plane Mach number cloud map contrast;

Fig. 5 is the blunt leading edge provided by the utility model and the traditional blunt leading edge centerline wall pressure comparison;

FIG. 6 is a comparison of the wall heat flow between the blunt leading edge provided by the present invention and the traditional blunt leading edge centerline.

Among them in Figure 1-3: 1- air inlet, 2- air outlet, 3- diversion channel, 4- straight section, 5- smooth transition section.

Detailed ways

The core of the utility model is to provide an air inlet to improve the performance of the air inlet.

In order to make those skilled in the art better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Please refer to Figure 1 to Figure 6.

In a specific embodiment, the air intake provided by the specific embodiment of the present invention, which is used in an engine, includes a blunt leading edge, and the blunt leading edge includes a smooth transition section 5 located in the center and a flat transition section connected to both ends of the smooth transition section. Straight section 4; the blunt leading edge is provided with an air inlet 1 and an air outlet 2, the air inlet 1 and the air outlet 2 are connected through the guide channel 3 at the position of the blunt leading edge, and the air inlet 1 and the center of the smooth transition section 5 are connected. The distance is smaller than the distance between the air outlet 2 and the center of the smooth transition section 5 . As shown in Fig. 1 to Fig. 3, the position of the blunt leading edge is a plate structure, which is to facilitate the display of the position of the diversion channel, the air inlet and the air outlet. In specific use, the position of the blunt leading edge is not the above shape.

Preferably, the air inlet 1 is opened at the center of the smooth transition section 5 , and the air outlet 2 is opened at the smooth transition section 5 or the straight section 4 or the connecting position of the straight section 4 and the smooth transition section 5 .

The air inlet 1 is perpendicular to the wall surface where the opening position of the smooth transition section 5 is located, and the air outlet 2 is along the spanwise coordinate (z-axis) direction.

When the engine is working, near the center of the smooth transition section 5, the shock wave interference is complex and the pressure is high; upstream of the smooth transition section 5, the pressure is low; using the static pressure difference between the upstream and downstream of the flow field, the center of the smooth transition section 5 is moved. The high-pressure airflow at the air inlet is drawn away from the air inlet 1, and is re-ejected from the air outlet 2 at the lower upstream pressure position through the guide channel 3 to realize a self-circulating flow control loop.

As can be seen from the above description, in the air inlet provided by the specific embodiment of the present application, by opening the guide channel 3 on the blunt leading edge, the static pressure difference between the upstream and downstream of the flow field is used to divert the high-pressure airflow at the center of the smooth transition section 5 from The air inlet 1 is drawn away, and through the guide channel 3, the air outlet 2 at the lower upstream pressure position is re-ejected, and the flow self-circulation can be realized without additional power device. The flow self-circulation can be realized without additional power device and energy supply system. The structure is simple and easy to implement. The airflow at the high pressure is directed to the low pressure position, which reduces the distance from the shock wave at the center of the smooth transition section 5 to the wall surface, effectively reducing the Blunt leading edge wall pressure and heat flow load peaks, thereby improving intake performance.

Preferably, there are two guide channels 3, and the two guide channels 3 are respectively arranged on opposite sides of the centerline of the blunt leading edge.

In a specific implementation method, the two guide channels 3 share one air inlet 1 , and the air inlet 1 is located at the center of the smooth transition section 5 .

Specifically, the center line of the smooth transition section 5 is an arc-shaped line structure, specifically a circular arc shape. Alternatively, the shape of the center line of the smooth transition section 5 is an elliptical structure, a hyperbolic shape, a parabolic shape, or the like.

In a specific embodiment, the air inlet 1 , the air outlet 2 and the guide channel 3 are all pipes with circular cross-sections.

In a specific embodiment, the guide channel and the air inlet 1 and the air outlet 2 are all smoothly transitioned by rounding;

The rounding radius R ₁ of the transition between the air inlet 1 and the guide channel 3 satisfies:

0.2r≤R ₁ ≤1r;

The rounding radius R ₂ of the transition between the air outlet 2 and the guide channel 3 satisfies:

0.5r≤R ₂ ≤4r;

r is the passivation radius of the blunt leading edge.

In a specific embodiment, the diameter D _{1 of the air inlet 1} satisfies:

0.3r≤D ₁ ≤0.4r, specifically, D ₁ may be 0.35r.

where r is the passivation radius of the blunt leading edge.

Specifically, the air outlet 2 and the diversion channel 3 are equal-section pipes, and the diameter D2 of the air outlet ₂ and the diversion channel 3 satisfies:

The air outlet 2 is located at the junction of the straight section and the smooth transition section 5, and the horizontal distance L1 between the center of the air outlet 2 and the center of the smooth transition section ₅ satisfies:

0.2r≤L ₁ ≤8r, specifically, 0.4r≤L ₁ ≤0.6r,

r is the passivation radius of the blunt leading edge.

The center of the air inlet 1 and the two starting points of the guide channel 3 are connected by a variable-section circular pipe.

In a specific embodiment, the connection between the air inlet 1 and the diversion channel 3 is connected by a variable-section circular pipe;

The horizontal distance L ₂ between the center of the air inlet 1 and the air inlet end of the guide channel 3 satisfies:

0.3r≤L ₂ ≤1r, specifically, 0.5r≤L ₂ ≤0.8r.

where r is the passivation radius of the blunt leading edge.

In a specific embodiment, referring to FIG. 3 , the design parameters of the self-circulating flow control device in this example are: the diameter of the air inlet 1 D ₁ =0.4r, the diameter of the air outlet 2 and the diversion channel 3 D ₂ = 0.283r, the horizontal distance between the center of the air outlet 2 and the center of the smooth transition section 5 L ₁ =1.9r, the horizontal distance between the center of the air inlet 1 and the air inlet end of the guide channel 3 L ₂ =0.3r, the air inlet 1 and the guide The rounding radius of the transition of the channel 3 is R ₁ =0.4r, and the rounding radius of the transition between the air outlet 2 and the guide channel 3 is R ₂ =0.5r, where r is the leading edge passivation radius. Through numerical simulation, the control effect of this example is described as follows:

Accompanying drawing 4 provides the contrast of the Mach number cloud diagram of the blunt leading edge symmetry plane using the flow control device in the present application and the traditional one without flow control, wherein, the incoming flow Mach number is 6, and the incoming flow direction is from left to right; from FIG. 4 It can be seen from the streamline of the control device that the air does enter from the air inlet 1 of the control device, flows through the diversion channel 3, and then ejects from the air outlet 2; The shock-to-wall distance at the center of segment 5 is reduced by about 33%.

Figure 5 shows the comparison of the wall pressure on the centerline of the blunt leading edge with flow control and the traditional one without flow control in the diversion channel 3. The horizontal axis is the spanwise coordinate divided by the leading edge passivation radius, and the vertical axis is the local pressure divided by the flow. Static pressure, the solid line in the figure represents the result without flow control, and the dashed line represents the result with flow control. It can be seen from Fig. 5 that between the inlet port 1 and the outlet port 2, there is an obvious peak pressure distribution on the wall surface, and after the flow control is adopted, the pressure peak value decreases by about 28%. That is to say, the self-circulating flow control device of the blunt leading edge of the present invention effectively reduces the peak pressure load on the wall surface of the blunt leading edge.

Figure 6 shows the comparison of the heat flow on the center line of the blunt leading edge with the traditional flow control and the traditional without flow control. The horizontal axis is the spanwise coordinate divided by the leading edge passivation radius, and the vertical axis is the local heat flow divided by the same passivation radius. The theoretical value of the stagnation point heat flow of , the solid line in the figure represents the result without flow control, and the dotted line represents the result with flow control. It can be seen from Fig. 6 that between the inlet port 1 and the outlet port 2, the heat flow distribution on the wall also has an obvious peak value, and after the flow control is adopted, the peak value of the heat flow load decreases by about 27%. It can be seen that the control effect is obvious.

When the application is working, near the center of the smooth transition section 5, the shock wave interference is complex and the pressure is high; upstream of the smooth transition section 5, the pressure is low; using the static pressure difference between the upstream and downstream of the flow field, the smooth transition section 5 The high-pressure air flow at the center is drawn away from the air inlet 1, and is re-ejected through the guide channel 3 at the air outlet 2 at the lower upstream position to realize a self-circulating flow control loop. In addition, the section of the diversion channel 3 is circular, which has little damage to the structure, and the length of the diversion channel 3 is short, which reduces the complexity of the device and increases the smoothness of the flow; It is the sum of the cross-sectional areas of the upper and lower outlets, which further increases the smoothness of the flow.

It can be seen from the technical solutions provided by the present utility model that the blunt leading edge self-circulating flow control device provided by the present utility model utilizes the static pressure difference between the upstream and downstream of the flow field, without the need for additional power devices and energy supply systems. Flow self-circulation, simple structure, easy to implement. On the premise of not changing the geometric characteristics of the blunt leading edge, the distance from the shock wave to the wall at the center of the smooth transition section 5 is significantly reduced, and the peak pressure and heat flow load on the blunt leading edge wall surface are effectively reduced. In addition, the self-circulating flow control device has a wide range of applications, and can be implemented for blunt leading edges with different geometric features.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (10)

1. An air inlet channel for an engine, characterized by comprising a blunt leading edge, wherein the blunt leading edge comprises a smooth transition section (5) at the center and a straight section (4) connected with two ends of the smooth transition section;

air inlet (1) and gas outlet (2) have been seted up on the blunt leading edge, air inlet (1) with gas outlet (2) pass through water conservancy diversion passageway (3) that the blunt leading edge position is connected, air inlet (1) with the distance at smooth transition section (5) center is less than gas outlet (2) with the distance at smooth transition section (5) center.

2. The air inlet according to claim 1, characterized in that the number of the flow guide channels (3) is two, and the two flow guide channels (3) are respectively arranged on two opposite sides of the centerline position of the blunt leading edge.

3. The intake duct according to claim 1, characterized in that two of the flow-guiding channels (3) share one of the intake openings (1), and the intake opening (1) is located in the center of the smooth transition section (5).

4. The intake duct according to claim 1, characterized in that the centre line of the smooth transition (5) is of circular arc configuration.

5. Air inlet duct according to claim 1, characterized in that the air inlet (1), the air outlet (2) and the flow guide channel (3) are all circular-section ducts.

6. Air intake duct according to claim 5, characterized in that the diameter D of the air intake opening (1)₁Satisfies the following conditions:

0.3r≤D₁≤0.4r；

two gas outlets (2) are distributed on two opposite sides of the center line of the blunt front edge and are symmetrically distributed, the gas outlets (2) and the flow guide channel (3) are equal-section pipelines, and the gas outlets(2) And the diameter D of the flow guide channel (3)₂Satisfies the following conditions:

where r is the passivation radius of the blunt leading edge.

7. The air inlet according to claim 6, characterized in that the air outlet (2) is located at the junction of the straight section (4) and the smooth transition section (5), and the horizontal distance L between the center of the air outlet (2) and the center of the smooth transition section (5)₁Satisfies the following conditions:

0.2r≤L₁≤8r。

8. the air inlet duct according to claim 1, characterized in that the connection of the air inlet (1) and the flow guide channel (3) is connected by a variable cross-section circular duct;

the horizontal distance L of the starting point of the joint of the center of the air inlet (1) and the flow guide channel (3)₂Satisfies the following conditions:

0.3r≤L₂≤1r；

where r is the passivation radius of the blunt leading edge.

9. The air inlet according to claim 1, characterized in that the flow guide channel (3) and the air inlet (1) and the air outlet (2) are smoothly transited by rounding;

the radius R of the transition between the air inlet (1) and the flow guide channel (3)₁Satisfies the following conditions:

0.2r≤R₁≤1r；

where r is the passivation radius of the blunt leading edge.

10. Air inlet according to claim 9, characterized in that the outlet opening (2) merges with the flow guide channel (3) with a rounding radius R₂Satisfies the following conditions:

0.5r≤R₂≤4r。

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