CN117404205A - S-bend pneumatic vector spray pipe with slit air film cooling structure - Google Patents

Abstract

The invention relates to an S-bend pneumatic vector spray pipe with a slit air film cooling structure, belonging to the field of aeroengines; the device comprises an S-shaped convergence section and a binary expansion section which are axially and sequentially arranged, wherein a secondary flow pneumatic vector structure with a slit air film cooling structure is arranged on at least one part of the peripheral surface of the binary expansion section, high-pressure cold air is split by the secondary flow pneumatic vector structure and then is introduced into a spray pipe, and a part of split cold air is injected into a main flow in the spray pipe from a pneumatic vector outlet, so that deflection force for changing the angle of the main flow can be generated; and the other part of split cold air flows out from a slit air film cooling outlet positioned at the upstream of the air vector outlet, and cools the wall surface at the upstream of the air vector outlet. The secondary flow pneumatic vector structure with the slit air film cooling structure is arranged at the expansion section of the spray pipe to control the deflection of the main flow and solve the problem that high-temperature fuel gas is eroded on the wall surface of the spray pipe caused by pneumatic vector jet flow.

Description

An S-bent aerodynamic vector nozzle with a slit film cooling structure

Technical field

The invention belongs to the field of aeroengines, and specifically relates to an S-bent aerodynamic vector nozzle with a slit air film cooling structure.

Background technique

The S-bent nozzle can effectively reduce the infrared signal and radar signal of the aircraft, so the S-bent nozzle will be used on aircraft performing missions. It is worth noting that thrust vector technology is used to improve the agility, over-stall maneuvering and short take-off and landing performance of fighter aircraft. It can partially or completely replace the aerodynamic rudder surface for flight control. It is one of the key technologies necessary for aircraft to perform missions. one. The fixed-geometry aerodynamic vector nozzle has become an exhaust system solution that has attracted much attention because it has a simpler structure, lighter weight, and faster response than the conventional mechanical thrust vector nozzle. The new generation of aircraft performing missions should have both stealth and aerodynamic vectoring capabilities, so the S-bend aerodynamic vectoring nozzle has become a research hotspot.

Applying aerodynamic vector technology to a double-duct S-bend nozzle will cause the high-temperature gas in the inner duct to flow near the wall and erode the nozzle wall upstream of the aerodynamic vector outlet. Shi Jingwei's paper "Research on the Effect of Secondary Flow Nozzle Shape in Shock Vector Nozzles" shows that for the supersonic mainstream, the injection of secondary flow is a strong source of disturbance, causing the formation of a bow-shaped induced shock wave in the mainstream. Waves will cause flow separation in the near-wall area and cause high-temperature gas in the inner duct to flow near the wall. The nozzle wall is easily deformed when washed by high-temperature gas, and the high-temperature nozzle wall and high-temperature exhaust gas are prone to produce large infrared radiation, which affects the stealth performance of the S-bend nozzle. Therefore, effective cooling measures need to be taken for the S-bend aerodynamic vector nozzle.

Contents of the invention

Technical issues to be resolved:

In order to avoid the shortcomings of the prior art, the present invention provides an S-bent aerodynamic vector nozzle with a slit air film cooling structure. By arranging a secondary flow aerodynamic vector with a slit air film cooling structure in the expansion section of the nozzle, structure to control the deflection of the mainstream and solve the problem of high-temperature gas erosion of the nozzle wall caused by aerodynamic vector jets.

The technical solution of the present invention is: an S-bend aerodynamic vector nozzle with a slit air film cooling structure, including an S-bend convergence section and a binary expansion section arranged in sequence in the axial direction. The peripheral surface of the binary expansion section A secondary flow aerodynamic vector structure with a slit air film cooling structure is provided at at least one place on the upper body. Through the secondary flow aerodynamic vector structure, the high-pressure cold air is diverted into the nozzle, and a part of the diverted cold air is ejected from the aerodynamic vector outlet. The main flow entering the nozzle can generate a deflection force that changes the angle of the main flow; the other part of the split cold air flows out from the slit air film cooling outlet located upstream of the aerodynamic vector outlet to cool the wall upstream of the aerodynamic vector outlet.

A further technical solution of the present invention is: the secondary flow aerodynamic vector structure with a slit air film cooling structure is a cold air channel located on the wall of the expansion section, and its secondary flow inlet faces outside the wall for introducing high-pressure cold air; The outlet includes a pneumatic vector outlet and a slit air film cooling outlet provided on the wall surface of the expansion section. Through the two outlets, the two airflows divided by the cold air channel are passed into the expansion section respectively.

A further technical solution of the present invention is that the cold air channel is a pipe that fits the outer wall of the expansion section, and the cold air in the main channel in the pipe sequentially passes through the secondary flow inlet, the secondary flow pipe, the pneumatic vector outlet and the main flow in the nozzle. Blending; there is a bypass on the secondary flow pipe. The bypass is a wall-adherent pipe located upstream of the secondary flow pipe. It is connected to the slit film cooling outlet. The cold air diverted by the bypass passes through the secondary flow pipe in turn. The inlet, secondary flow pipe, wall-adherent pipe, and slit air film cooling outlet flow into the inner wall surface of the expansion section upstream of the pneumatic vector outlet.

A further technical solution of the present invention is that the injection direction of the cold air from the main channel in the pipeline is perpendicular to the axial direction of the expansion section.

A further technical solution of the present invention is that the jet angle of the cold air diverted by the bypass is 50°-130°.

A further technical solution of the present invention is that the ratio of the secondary flow inlet area to the outlet area of the S-bend nozzle convergence section is 0.05-0.12.

A further technical solution of the present invention is that the ratio of the pneumatic vector outlet area to the secondary flow inlet area is 0.5-1.5.

A further technical solution of the present invention is that the ratio of the slit air film cooling outlet area to the aerodynamic vector outlet area is 0.05-0.5.

A further technical solution of the present invention is that the distance between the pneumatic vector outlet and the slit air film cooling outlet is 5-10 times the width of the secondary flow pipe along the flow direction.

A further technical solution of the present invention is that two secondary flow aerodynamic vector structures with slit air film cooling structures are symmetrically arranged on the upper and lower wall surfaces of the binary expansion section for controlling the upper and lower deflection of the main stream of the nozzle. .

beneficial effects

The beneficial effects of the present invention are: the present invention proposes an S-bend aerodynamic vector nozzle with a slit air film cooling structure, which consists of an S-bend convergence section, a binary expansion section and a secondary flow with a slit air film cooling structure. Composed of aerodynamic vector structure. The high-pressure cold air flows into the secondary flow aerodynamic vector structure with a slit air film cooling structure through the secondary flow inlet. Most of the cold air flows out through the aerodynamic vector outlet, thereby controlling the upward and downward deflection of the mainstream; at the same time, the split flow design is used to solve the problem of aerodynamic vector injection The high-temperature gas erosion caused by the flow causes the problem of nozzle wall surface.

Preferably, the ratio of the secondary flow inlet area to the exit area of the convergence section of the S-bend nozzle is controlled to be 0.05-0.12. If the secondary flow outlet area is too small, the flow rate of cold air flowing out will also be small, and the deflection angle of the mainstream will also be too small. However, if the secondary flow outlet area is too large, the demand for secondary flow air supply will increase, which is not conducive to the operation of the aeroengine.

Preferably, the ratio of the slit air film cooling outlet area to the aerodynamic vector outlet area is 0.05-0.5. The flow rate flowing through the wall-adhering pipe is controlled by changing the slit air film cooling outlet area, thereby ensuring that a small amount of cold air flows into the wall-adhering pipe. (The pressure of the secondary air flow should be adjusted according to the total inlet pressure of the main stream of the nozzle. Since the main stream flows to the secondary flow aerodynamic vector structure with a slit air film cooling structure, it has already gone through the process of accelerated pressure reduction. As long as it is ensured The secondary flow pressure is greater than or equal to the total pressure at the nozzle inlet, which ensures that the cooling airflow flows out from the aerodynamic vector outlet and the slit air film cooling outlet); when the cold air flows in the wall-adherent pipe, the cold air will face the outer wall of the nozzle Flow heat transfer cools the outer wall of the nozzle; the cold air flowing through the wall-adherent pipe flows out through the slit air film cooling outlet and covers the inner wall upstream of the aerodynamic vector outlet, thereby reducing the temperature of the inner wall of the nozzle.

Preferably, ensure that the distance between the pneumatic vector outlet and the slit film cooling outlet is 5-10 times the width of the secondary flow pipe along the flow direction. This distance is also the wall area where gas erosion is prone to occur. This invention uses air film cooling for the first time in the field of aerodynamic vector technology. On the basis of meeting the thrust vector characteristics of the S-bend nozzle, it reduces the temperature and infrared radiation of the nozzle wall and solves the high-temperature gas erosion caused by the aerodynamic vector jet. Problems with the nozzle wall.

Description of the drawings

Figure 1 is a schematic diagram of an S-bend aerodynamic vector nozzle with a slit air film cooling structure according to an embodiment of the present invention;

Figure 2 is a partial enlarged view of the secondary flow aerodynamic vector structure with a slit film cooling structure;

Explanation of reference signs: 1. S-bend convergence section; 11. Air inlet; 2. Binary expansion section; 21. Exhaust port; 3. Secondary flow aerodynamic vector structure with slit air film cooling structure; 31. Secondary flow inlet; 32. Secondary flow pipe; 33. Wall-adherent pipe; 34. Pneumatic vector outlet; 35. Slit air film cooling outlet.

Detailed ways

The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The directions indicated by "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" etc. or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, Therefore, it should not be construed as a limitation of the present invention.

Based on the existing technology that the nozzle wall is easily deformed when washed by high-temperature gas, and the high-temperature nozzle wall and the high-temperature exhaust gas are prone to produce large infrared radiation, which affects the stealth performance of the S-bend nozzle, the present invention provides a An S-bend aerodynamic vector nozzle with a slit air film cooling structure, including an S-bend convergence section and a binary expansion section arranged sequentially in the axial direction. At least one of the peripheral surfaces of the binary expansion section is provided with a tape. The secondary flow aerodynamic vector structure of the slit film cooling structure divides the high-pressure cold air into the nozzle through the secondary flow aerodynamic vector structure, and a part of the divided cold air is injected into the mainstream in the nozzle from the aerodynamic vector outlet, which can A deflection force is generated that changes the angle of the mainstream; the other part of the split cold air flows out from the slit air film cooling outlet located upstream of the aerodynamic vector outlet to cool the wall upstream of the aerodynamic vector outlet.

Specifically, the secondary flow aerodynamic vector structure with the slit air film cooling structure is a cold air channel located on the wall of the expansion section, with the secondary flow inlet facing outside the wall for introducing high-pressure cold air; its outlet includes a cooling air channel located on the expansion section wall. The aerodynamic vector outlet and the slit air film cooling outlet on the section wall pass the two airflows diverted from the cold air channel into the expansion section respectively.

Specifically, the cold air channel is a pipe that fits the outer wall of the expansion section, and the cold air in the main channel in the pipe sequentially passes through the secondary flow inlet, the secondary flow pipe, the pneumatic vector outlet and is mixed with the mainstream in the nozzle; There is a bypass on the secondary flow pipe. This bypass is a wall-adherent pipe located upstream of the secondary flow pipe. It is connected to the slit film cooling outlet. The cold air diverted by the bypass passes through the secondary flow inlet, the secondary flow inlet, and the secondary flow inlet. The flow pipe, the wall-adherent pipe, and the slit air film cooling outlet flow into the inner wall surface of the expansion section upstream of the pneumatic vector outlet.

The high-pressure cold air flows into the secondary flow aerodynamic vector structure with a slit air film cooling structure through the secondary flow inlet. Most of the cold air flows out through the aerodynamic vector outlet, thereby controlling the upward and downward deflection of the mainstream; at the same time, the split flow design is used to solve the problem of aerodynamic vector injection The high-temperature gas erosion caused by the flow causes the problem of nozzle wall surface.

The above technical solution will be further explained below with reference to the accompanying drawings:

This embodiment takes the S-bend aerodynamic vector nozzle as an example to illustrate the implementation of the S-bend aerodynamic vector nozzle with a slit air film cooling structure. In addition to the S-bend aerodynamic vector nozzle, the binary aerodynamic vector nozzle and the axially symmetric aerodynamic vector nozzle The slit air film cooling method can be used for cooling design of tubes, etc., which will not be explained here.

Referring to Figure 1, the S-bend aerodynamic vector nozzle of this embodiment includes an S-bend convergence section 1 whose cross-sectional shape transitions from circular to rectangular, and a binary expansion section 2 whose cross-sectional shape is all rectangular. The S-bend convergence section The first end of 1 has an air inlet 11 connected to the high-temperature turbine outlet of the engine. This embodiment is mainly used in turbofan engines. The air inlet 11 is divided into a high-temperature inner inlet and a low-temperature outer inlet. The low-temperature airflow in the outer duct can well cover the nozzle wall, preventing the inner high-temperature airflow from ablating the nozzle wall. The second end of the binary expansion section 2 is the exhaust port 21, and the second end of the S-bend convergence section 1 is connected end-to-end with the first end of the binary expansion section 2.

Referring to Figure 2, it is a partial enlarged view of the secondary flow aerodynamic vector structure 3 with a slit air film cooling structure. The secondary flow aerodynamic vector structure 3 with a slit air film cooling structure consists of a secondary flow inlet 31, two It consists of a secondary flow pipe 32, a wall-adherent pipe 33, a pneumatic vector outlet 34 and a slit air film cooling outlet 35, and is arranged on the upper or lower wall surface of the binary expansion section 2. The secondary flow pipe 32 and the wall-adherent pipe 33 are rectangular pipes. The basic injection angle of the secondary flow pipe 32 is 90°, that is, the angle between the cross section of the secondary flow pipe and the cross section of the nozzle. The secondary flow injection angle is The selection range is 50°-130°. The wall-adhering pipe 33 is parallel to the wall of the nozzle, and the secondary flow pipe 32 is connected with the wall-adhering pipe 33 . The pneumatic vector outlet 34 is located downstream of the slit air film cooling outlet 35; the high-pressure cold air flows into the secondary flow jet structure 3 with the slit air film cooling structure through the secondary flow inlet 31, and most of the cold air flows out through the pneumatic vector outlet 34, thus Control the upward and downward deflection of the main stream; a small amount of cold air flows into the wall-adherent pipe 33 and flows out through the slit air film cooling outlet 35 to cool the wall upstream of the aerodynamic vector outlet 34, thus solving the problem of high-temperature gas erosion of the nozzle caused by the aerodynamic vector jet. Wall problem.

Specifically, the ratio of the area of the secondary flow inlet 31 to the outlet area of the S-bend nozzle convergence section 1 is 0.05-0.12; the ratio of the area of the aerodynamic vector outlet 34 to the area of the secondary flow inlet 31 is 0.5-1.5; slit air film cooling The ratio of the area of the outlet 35 to the area of the pneumatic vector outlet 34 is 0.05-0.5; the distance between the pneumatic vector outlet 34 and the slit film cooling outlet 35 is 5-10 times the width of the secondary flow pipe 32 along the flow direction.

In this embodiment, the high-pressure cold air flows into the secondary flow pneumatic vector structure 3 with a slit air film cooling structure through the secondary flow inlet 31, and most of the cold air flows out through the pneumatic vector outlet 34, thereby controlling the upward and downward deflection of the main flow; less Part of the cold air flows into the wall-attached pipe 33. When the cold air flows in the wall-attached pipe, the cold air will flow with the outer wall of the nozzle to exchange heat, cooling the outer wall of the nozzle; the cold air flowing through the wall-attached pipe 33 is cooled by the slit air film The outlet 35 flows out and covers the inner wall upstream of the aerodynamic vector outlet 34, thereby reducing the temperature of the inner wall of the nozzle, reducing the infrared radiation of the S-bent aerodynamic vector nozzle, and solving the problem of high-temperature gas erosion caused by the aerodynamic vector jet. Problems with the pipe wall.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and should not be construed as limitations of the present invention. Those of ordinary skill in the art will not deviate from the principles and purposes of the present invention. Under the circumstances, the above-described embodiments can be changed, modified, replaced and modified within the scope of the present invention.

Claims (10)

1. S-bend pneumatic vector spray pipe with slit air film cooling structure comprises an S-bend convergence section and a binary expansion section which are axially and sequentially arranged, and is characterized in that: the secondary flow pneumatic vector structure with the slit air film cooling structure is arranged on at least one part of the peripheral surface of the binary expansion section, high-pressure cold air is split by the secondary flow pneumatic vector structure and then is introduced into the spray pipe, and part of split cold air is injected into the main flow in the spray pipe from the pneumatic vector outlet, so that deflection force for changing the angle of the main flow can be generated; and the other part of split cold air flows out from a slit air film cooling outlet positioned at the upstream of the air vector outlet, and cools the wall surface at the upstream of the air vector outlet.

2. The S-bend air vector nozzle with slit film cooling structure of claim 1, wherein: the secondary flow pneumatic vector structure with the slit air film cooling structure is a cold air channel positioned on the wall surface of the expansion section, and a secondary flow inlet of the secondary flow pneumatic vector structure faces to the outside of the wall surface and is used for introducing high-pressure cold air; the outlet comprises a pneumatic vector outlet and a slit air film cooling outlet which are arranged on the wall surface of the expansion section, and two air flows which are split by the cold air channel are respectively led into the expansion section through the two outlets.

3. The S-bend air vector nozzle with slit film cooling structure of claim 2, wherein: the cold air channel is a pipeline attached to the outer wall surface of the expansion section, and cold air of the main channel in the pipeline is mixed with the main flow in the spray pipe sequentially through the secondary flow inlet, the secondary flow pipeline and the pneumatic vector outlet; and a bypass is arranged on the secondary flow pipeline, the bypass is an adherence pipeline positioned at the upstream of the secondary flow pipeline and communicated with the slit air film cooling outlet, and cold air shunted by the bypass flows into the inner wall surface of the expansion section at the upstream of the pneumatic vector outlet through the secondary flow inlet, the secondary flow pipeline, the adherence pipeline and the slit air film cooling outlet in sequence.

4. An S-bend air vector nozzle with slit film cooling structure according to claim 3, wherein: the jetting direction of the cold air of the main channel in the pipeline is perpendicular to the axial direction of the expansion section.

5. The S-bend air vector nozzle with slit film cooling structure of claim 4, wherein: the jet angle of the cold air which is bypassed is 50-130 degrees.

6. An S-bend pneumatic vector nozzle with slit film cooling structure according to any one of claims 1-5, wherein: the ratio of the area of the secondary flow inlet to the area of the outlet of the convergent section of the S-bend spray pipe is 0.05-0.12.

7. The S-bend air vector nozzle with slit film cooling structure of claim 6, wherein: the ratio of the area of the pneumatic vector outlet to the area of the secondary flow inlet is 0.5-1.5.

8. The S-bend air vector nozzle with slit film cooling structure of claim 7, wherein: the ratio of the area of the slit air film cooling outlet to the area of the pneumatic vector outlet is 0.05-0.5.

9. The S-bend air vector nozzle with slit film cooling structure of claim 8, wherein: the distance between the pneumatic vector outlet and the slit air film cooling outlet is 5-10 times of the width of the secondary flow pipeline along the flow direction.

10. The S-bend air vector nozzle with slit film cooling structure of claim 9, wherein: the upper and lower wall surfaces of the binary expansion section are symmetrically provided with two secondary flow pneumatic vector structures with slit air film cooling structures, and the secondary flow pneumatic vector structures are used for controlling the upper and lower deflection of the main flow of the spray pipe.