Device and method for improving jet flow precooling heat exchange effect by injecting incoming flow

Abstract

According to the device and method for improving the jet flow pre-cooling heat exchange effect through the incoming flow injection, on the basis of a wing-shaped jet flow support, the incoming flow injection technology is adopted, the windward area is reduced by arranging a front edge opening in a standing point of the windward side of the support, the air pressure loss and the air stagnation condition are avoided, and high-speed air flow on the front edge of the support can be introduced into a cooling channel; the cooling fins in the cooling channel are used for cooling the high-speed air flow, and the cooled high-speed air flow can be guided to the two sides and the tail edge of the support respectively through three paths of shunting. Airflows on the two sides of the supports can be ejected in the direction perpendicular to the side wall faces of the supports, the jet flow can increase the spanwise speed and diffusion uniformity of cooling medium liquid drops, the liquid drops ejected oppositely between the adjacent supports collide, the particle size of the liquid drops can be reduced, and the jet flow precooling effect is further improved. And for airflow ejected from the tail edge of the support, backflow at the tail edge can be effectively reduced, generation of non-uniform wakes is further restrained, and the obvious improvement effect on reduction of support resistance and improvement of temperature distribution uniformity is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of cooling the air intake of an aero-engine, and in particular relates to a device and a method for improving the jet precooling heat exchange effect by introducing a jet flow. Background Art

[0002] Hypersonic vehicles have become one of the technological commanding heights in the field of aerospace, and high-speed aircraft engines are the key to achieving high Mach number flight for hypersonic vehicles. At present, aviation turbine engines mainly operate at flight Mach numbers of 0 to 2, and subsonic ramjet engines mainly operate at flight Mach numbers of 3 to 6. It can be seen that any single engine cannot meet the power requirements from low speed to hypersonic speed.

[0003] To this end, the concept of combining aviation turbine engines and ramjet engines to form a parallel engine (Turbine Based Combined Cycle, TBCC for short) was proposed. Although the TBCC engine technically integrates the advantages of aviation turbine engines and ramjet engines in their respective flight Mach ranges, how to achieve the high Mach conversion point of aviation turbine engines and ramjet engines under the condition of flow matching has become the main problem of aviation turbine engines at present.

[0004] At present, there are still defects in the continuity of the TBCC engine's mode conversion process, and it is necessary to improve the working upper limit of the aviation turbine engine to achieve smooth mode conversion. Currently, pre-cooling the incoming air of the aviation turbine engine, that is, by injecting cooling medium into the inlet duct and using the phase change heat absorption of the cooling medium to achieve air jet pre-cooling, is one of the effective means to improve the upper limit of the working performance of the aviation turbine engine.

[0005] At present, in order to achieve jet pre-cooling, it is usually necessary to set up multiple jet brackets with jet nozzles in the air inlet duct, but the jet bracket will also produce an obstruction effect. This obstruction will directly cause the loss of air pressure and air stagnation, resulting in the incoming air to produce a low-speed and high-temperature narrow tail at the tail of the jet bracket, which is obviously unfavorable to the effect of jet pre-cooling.

[0006] In addition, the droplet size of the jet nozzle is small, so the droplet has better followability, but this will cause the droplet to have a smaller spanwise velocity after being sprayed into the inlet duct, resulting in poor cooling uniformity. Since the traditional jet bracket does not consider measures to increase the penetration distance of the droplets between brackets, the traditional jet bracket still has obvious deficiencies in dealing with air flow loss and heat exchange uniformity. In addition, the stagnation point on the windward side of the traditional jet bracket will form high temperature under the effect of obstruction, and this high temperature will also affect the service life and reliability of the jet bracket. Therefore, it is necessary to optimize the structure of the jet bracket to improve the jet precooling effect. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a device and method for improving the jet precooling heat exchange effect by introducing an inflow, based on an airfoil jet bracket, adopting an inflow introduction technology, and arranging a leading edge opening at a stagnation point on the windward surface of the airfoil jet bracket to achieve a significant reduction in the windward area of ​​the airfoil jet bracket, effectively avoiding the loss of air pressure and air stagnation, and can introduce the high-speed airflow at the leading edge of the airfoil jet bracket into the cooling channel, and further cool the high-speed airflow with the help of cooling fins in the cooling channel, and the cooled high-speed airflow can be respectively guided to the two sides and the trailing edge of the airfoil jet bracket through three-way diversion; for the airflow from the airfoil jet bracket The airflow ejected from both sides of the flow bracket will be ejected perpendicular to the side wall of the bracket. The jet will effectively increase the spanwise velocity of the jet droplets, thereby effectively enhancing the diffusion uniformity of the droplets. The droplets ejected in opposite directions between adjacent airfoil jet brackets will collide due to the increase in spanwise velocity, thereby achieving a further reduction in droplet size through high-speed collisions between droplets. The further reduction in droplet size can effectively improve the effect of jet precooling. For the airflow ejected from the trailing edge of the airfoil jet bracket, the backflow at the trailing edge can be effectively reduced, further suppressing the generation of uneven wakes, which has a significant improvement effect on reducing bracket resistance and improving temperature distribution uniformity.

[0008] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a device for improving the jet pre-cooling heat exchange effect by introducing an incoming flow, comprising an airfoil jet bracket and an air inlet duct, wherein the number of the airfoil jet brackets is several, and the several airfoil jet brackets are evenly arranged in a straight line in the air inlet duct; both ends of the airfoil jet bracket in the span direction are fixedly connected to the air inlet duct by bolt fastening assemblies, a cooling medium channel is opened inside the airfoil jet bracket, and a plurality of jet nozzles are distributed on the two side walls of the airfoil jet bracket, and the jet nozzles are connected to the cooling medium channel; a cooling medium inlet is arranged at the span-wise end of the airfoil jet bracket, and the cooling medium inlet is connected to the cooling medium channel; an introduced incoming flow structure is arranged on the airfoil jet bracket.

[0009] The induced flow structure includes a leading edge opening, a lateral opening and a trailing edge opening; the leading edge opening is arranged at a stagnation point on the windward surface of the leading edge of the airfoil jet bracket; there are two lateral openings, which are symmetrically arranged on the two side walls of the airfoil jet bracket, and jet nozzles are distributed on both sides of the front and rear of the lateral openings; the trailing edge opening is arranged at the trailing edge of the airfoil jet bracket.

[0010] A cooling channel, a jet side channel and a jet tail channel are provided inside the airfoil jet support; the leading edge opening is located at the air inlet side of the cooling channel and is connected thereto; the lateral opening is located at the air outlet side of the jet side channel and is connected thereto; the trailing edge opening is located at the air outlet side of the jet tail channel and is connected thereto; the air outlet side of the cooling channel is connected to the air inlet sides of the jet side channel and the jet tail channel.

[0011] A plurality of cooling fins are arranged inside the cooling channel. The cooling fins are hollow structures. A cooling medium is passed into the inner cavity of the cooling fins. The inner cavity of the cooling fins is connected with the cooling medium inlet through a hose.

[0012] The cooling fins are distributed in an evenly spaced and staggered order in the cooling channel along the chord length direction of the airfoil-shaped jet support.

[0013] The upper and lower ends of the cooling fin are connected to the airfoil jet support through a spring, and the cooling fin has a rotational freedom around the central axis of the spring.

[0014] A lateral flow regulating diverter plate is arranged on the air inlet side of the jet side channel, a lateral flow regulating motor is arranged on the spanwise end of the airfoil jet bracket, and a motor shaft of the lateral flow regulating motor is connected to the lateral flow regulating diverter plate.

[0015] A trailing edge flow regulating diverter plate is arranged on the air inlet side of the jet tail channel, and a trailing edge flow regulating motor is arranged at the spanwise end of the airfoil jet bracket, and the motor shaft of the trailing edge flow regulating motor is connected to the trailing edge flow regulating diverter plate.

[0016] The length of the leading edge opening is 1% to 99% of the span-wise height of the airfoil jet support, and the width of the leading edge opening is 10% to 90% of the maximum width of the leading edge of the airfoil jet support; the length of the trailing edge opening is 1% to 99% of the span-wise height of the airfoil jet support, and the width of the trailing edge opening is 10% to 90% of the width of the trailing edge of the airfoil jet support.

[0017] A method for improving the jet precooling heat exchange effect by introducing a flow, using the device for improving the jet precooling heat exchange effect by introducing a flow, specifically comprising:

[0018] The high-speed airflow in the air inlet first enters the cooling channel through the leading edge opening, and further contacts the cooling fins to achieve heat exchange cooling. The cooling fins will be deflected under the impact of the high-speed airflow, allowing the high-speed airflow to pass through the cooling channel smoothly. When the high-speed airflow moves to the outlet side of the cooling channel, a three-way flow split will be formed, two of which will enter the jet side channel through the opened lateral flow regulating splitter plate, and finally ejected from the airfoil jet bracket on the outlet side of the jet side channel. At this time, the cooling medium droplets ejected from the jet nozzle will be on the jet side. The airflow ejected from the channel increases the spanwise velocity to enhance the uniformity of cooling medium droplet diffusion. At the same time, the cooling medium droplets ejected in opposite directions from adjacent airfoil jet supports collide to reduce the particle size of the cooling medium droplets, thereby further improving the jet precooling effect. For the last of the three-way diversions, it will enter the jet tail channel through the opened trailing edge flow regulating diverter plate, and finally eject the airfoil jet support through the outlet side of the jet tail channel to reduce the backflow at the trailing edge and further suppress the generation of uneven wakes.

[0019] Beneficial effects of the present invention:

[0020] The device and method for improving the jet precooling heat exchange effect by introducing the incoming flow of the present invention are based on the airfoil jet bracket and adopt the introduced incoming flow technology. By setting the leading edge opening at the stagnation point of the windward surface of the airfoil jet bracket, the windward area of ​​the airfoil jet bracket is greatly reduced, and the loss of air pressure and air stagnation are effectively avoided. The high-speed airflow at the leading edge of the airfoil jet bracket can be introduced into the cooling channel, and the high-speed airflow is further cooled by the cooling fins in the cooling channel. The cooled high-speed airflow can be respectively introduced to the two sides and the trailing edge of the airfoil jet bracket through three-way diversion; for the high-speed airflow introduced from the two sides of the airfoil jet bracket, the high-speed airflow can be introduced to the two sides and the trailing edge of the airfoil jet bracket through three-way diversion. The airflow will be ejected perpendicular to the side wall of the bracket. The jet will effectively increase the spanwise velocity of the jet droplets, thereby effectively enhancing the diffusion uniformity of the droplets. The droplets ejected in opposite directions between adjacent airfoil jet brackets will collide due to the increase in spanwise velocity, thereby achieving a further reduction in droplet size through high-speed collisions between droplets. The further reduction in droplet size can effectively improve the effect of jet precooling. For the airflow ejected from the trailing edge of the airfoil jet bracket, the backflow at the trailing edge can be effectively reduced, further suppressing the generation of uneven wakes, which has a significant improvement effect on reducing bracket resistance and improving temperature distribution uniformity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of a device for improving the jet precooling heat exchange effect by introducing jet flow according to the present invention;

[0022] Figure 2 A front view of the leading edge of the airfoil jet support of the present invention;

[0023] Figure 3 for Figure 2 Middle AA section view;

[0024] In the figure, 1 is an airfoil jet bracket, 2 is an air inlet, 3 is a bolt fastening assembly, 4 is a jet nozzle, 5 is a cooling medium inlet, 6 is a leading edge opening, 7 is a lateral opening, 8 is a trailing edge opening, 9 is a cooling channel, 10 is a jet side channel, 11 is a jet tail channel, 12 is a cooling fin, 13 is a spring, 14 is a lateral flow regulating diverter plate, 15 is a trailing edge flow regulating diverter plate, and 16 is a cooling medium channel. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 3 As shown, a device for improving the jet precooling heat exchange effect by introducing an incoming flow comprises an airfoil jet bracket 1 and an air inlet 2, wherein the number of the airfoil jet brackets 1 is several, and the several airfoil jet brackets 1 are evenly arranged in a straight line in the air inlet 2; both ends of the airfoil jet bracket 1 in the span direction are fixedly connected to the air inlet 2 by bolt fastening assemblies 3, a cooling medium channel 16 is opened inside the airfoil jet bracket 1, and a plurality of jet nozzles 4 are distributed on the two side walls of the airfoil jet bracket 1, and the jet nozzles 4 are connected to the cooling medium channel 16; a cooling medium inlet 5 is provided at the span direction end of the airfoil jet bracket 1, and the cooling medium inlet 5 is connected to the cooling medium channel 16; an introducing incoming flow structure is provided on the airfoil jet bracket 1.

[0027] The induced flow structure includes a leading edge opening 6, a lateral opening 7 and a trailing edge opening 8; the leading edge opening 6 is arranged at the windward stagnation point of the leading edge of the airfoil jet bracket 1; there are two lateral openings 7, which are symmetrically arranged on the two side walls of the airfoil jet bracket 1, and jet nozzles 4 are distributed on both sides of the front and rear of the lateral openings 7; the trailing edge opening 8 is arranged at the trailing edge of the airfoil jet bracket 1.

[0028] A cooling channel 9, a jet side channel 10 and a jet tail channel 11 are provided inside the airfoil jet bracket 1; the leading edge opening 6 is located on the air inlet side of the cooling channel 9 and is connected thereto; the lateral opening 7 is located on the air outlet side of the jet side channel 10 and is connected thereto; the trailing edge opening 8 is located on the air outlet side of the jet tail channel 11 and is connected thereto; the air outlet side of the cooling channel 9 is connected to the air inlet sides of the jet side channel 10 and the jet tail channel 11.

[0029] A plurality of cooling fins 12 are arranged inside the cooling channel 9. The cooling fins 12 are hollow structures. A cooling medium is introduced into the inner cavity of the cooling fins 12. The inner cavity of the cooling fins 12 is connected to the cooling medium inlet 5 through a hose.

[0030] The cooling fins 12 are distributed in the cooling channel 9 at equal intervals and in a staggered order along the chord length direction of the airfoil jet support 1 .

[0031] The upper and lower ends of the cooling fin 12 are connected to the airfoil jet support 1 through a spring 13 , and the cooling fin 12 has a rotational freedom around the central axis of the spring 13 .

[0032] A lateral flow regulating diverter plate 14 is arranged on the air inlet side of the jet side channel 10 , and a lateral flow regulating motor is arranged on the spanwise end of the airfoil jet bracket 1 , and the motor shaft of the lateral flow regulating motor is connected to the lateral flow regulating diverter plate 14 .

[0033] A trailing edge flow regulating diverter plate 15 is provided on the air inlet side of the jet tail channel 11 , and a trailing edge flow regulating motor is provided at the spanwise end of the airfoil jet support 1 , and the motor shaft of the trailing edge flow regulating motor is connected to the trailing edge flow regulating diverter plate 15 .

[0034] The length of the leading edge opening 6 is 1% to 99% of the span-wise height of the airfoil jet bracket 1, and the width of the leading edge opening 6 is 10% to 90% of the maximum width of the leading edge of the airfoil jet bracket 1; the length of the trailing edge opening 8 is 1% to 99% of the span-wise height of the airfoil jet bracket 1, and the width of the trailing edge opening 8 is 10% to 90% of the trailing edge width of the airfoil jet bracket 1.

[0035] In this embodiment, the length of the leading edge opening 6 is 85% of the span-wise height of the airfoil jet bracket 1, and the width of the leading edge opening 6 is 20% of the maximum width of the leading edge of the airfoil jet bracket 1; the length of the trailing edge opening 8 is 90% of the span-wise height of the airfoil jet bracket 1, and the width of the trailing edge opening 8 is 20% of the trailing edge width of the airfoil jet bracket 1; the cooling medium introduced into the cooling medium inlet 5 is water, and the particle size of the cooling medium droplets sprayed from the jet nozzle 4 is 30 μm; the opening of the lateral flow regulating diverter plate 14 is adjusted so that the real-time flow of the jet side channel 10 reaches 10% of the maximum flow of the jet side channel 10; the opening of the trailing edge flow regulating diverter plate 15 is adjusted so that the real-time flow of the jet tail channel 11 reaches 10% of the maximum flow of the jet tail channel 11.

[0036] A method for improving the jet precooling heat exchange effect by introducing a flow, using the device for improving the jet precooling heat exchange effect by introducing a flow, specifically comprising:

[0037] The high-speed airflow in the air inlet 2 first enters the cooling channel 9 through the leading edge opening 6, and further contacts the cooling fins 12 to achieve heat exchange cooling, and the cooling fins 12 will be deflected under the impact of the high-speed airflow, so that the high-speed airflow can smoothly pass through the cooling channel 9; when the high-speed airflow moves to the outlet side of the cooling channel 9, a three-way flow will be formed, two of which will enter the jet side channel 10 through the opened lateral flow regulating diverter plate 14, and finally ejected from the airfoil jet bracket 1 through the outlet side of the jet side channel 10, at which time the cooling medium droplets ejected from the jet nozzle 4 will Under the action of the airflow ejected from the jet side channel 10, the spanwise velocity is increased to enhance the uniformity of the diffusion of the cooling medium droplets. At the same time, the cooling medium droplets ejected in opposite directions from adjacent airfoil jet brackets 1 will collide to reduce the particle size of the cooling medium droplets, thereby further improving the jet precooling effect. For the last of the three-way diversions, it will enter the jet tail channel 11 through the opened trailing edge flow regulating diverter plate 15, and finally eject the airfoil jet bracket 1 through the outlet side of the jet tail channel 11, so as to reduce the backflow at the trailing edge and further suppress the generation of uneven wakes.

[0038] The solutions in the embodiments are not intended to limit the protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the protection scope of the present invention.

Claims

1. A device for improving the jet precooling heat exchange effect by introducing jet flow, characterized in that: It includes an airfoil jet bracket and an air inlet duct, wherein the number of the airfoil jet brackets is several, and the several airfoil jet brackets are evenly arranged in a straight line in the air inlet duct; both ends of the airfoil jet bracket in the span direction are fixedly connected to the air inlet duct through bolt fastening components, a cooling medium channel is opened inside the airfoil jet bracket, and a plurality of jet nozzles are distributed on the two side walls of the airfoil jet bracket, and the jet nozzles are connected to the cooling medium channel; a cooling medium inlet is arranged at the span-wise end of the airfoil jet bracket, and the cooling medium inlet is connected to the cooling medium channel; an inlet flow introduction structure is arranged on the airfoil jet bracket.

2. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 1, characterized in that: The induced flow structure includes a leading edge opening, a lateral opening and a trailing edge opening; the leading edge opening is arranged at a stagnation point on the windward surface of the leading edge of the airfoil jet bracket; there are two lateral openings, which are symmetrically arranged on the two side walls of the airfoil jet bracket, and jet nozzles are distributed on both sides of the front and rear of the lateral openings; the trailing edge opening is arranged at the trailing edge of the airfoil jet bracket.

3. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 2, characterized in that: A cooling channel, a jet side channel and a jet tail channel are provided inside the airfoil jet support; the leading edge opening is located at the air inlet side of the cooling channel and is connected thereto; the lateral opening is located at the air outlet side of the jet side channel and is connected thereto; the trailing edge opening is located at the air outlet side of the jet tail channel and is connected thereto; the air outlet side of the cooling channel is connected to the air inlet sides of the jet side channel and the jet tail channel.

4. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 3, characterized in that: A plurality of cooling fins are arranged inside the cooling channel. The cooling fins are hollow structures. A cooling medium is passed into the inner cavity of the cooling fins. The inner cavity of the cooling fins is connected with the cooling medium inlet through a hose.

5. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 4, characterized in that: The cooling fins are distributed in a staggered order at equal intervals in the cooling channel along the chord length direction of the airfoil-shaped jet support.

6. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 4, characterized in that: The upper and lower ends of the cooling fin are connected to the airfoil jet support through a spring, and the cooling fin has a rotational freedom around the central axis of the spring.

7. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 3, characterized in that: A lateral flow regulating diverter plate is arranged on the air inlet side of the jet side channel, a lateral flow regulating motor is arranged on the spanwise end of the airfoil jet bracket, and a motor shaft of the lateral flow regulating motor is connected to the lateral flow regulating diverter plate.

8. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 3, characterized in that: A trailing edge flow regulating diverter plate is arranged on the air inlet side of the jet tail channel, and a trailing edge flow regulating motor is arranged at the spanwise end of the airfoil jet bracket, and the motor shaft of the trailing edge flow regulating motor is connected to the trailing edge flow regulating diverter plate.

9. The device for improving the jet precooling heat exchange effect by jetting flow according to claim 2, characterized in that: The length of the leading edge opening is 1% to 99% of the span-wise height of the airfoil jet support, and the width of the leading edge opening is 10% to 90% of the maximum width of the leading edge of the airfoil jet support; the length of the trailing edge opening is 1% to 99% of the span-wise height of the airfoil jet support, and the width of the trailing edge opening is 10% to 90% of the width of the trailing edge of the airfoil jet support.

10. A method for improving the jet precooling heat exchange effect by introducing a flow, using the device for improving the jet precooling heat exchange effect by introducing a flow as claimed in claim 1, characterized in that: Specifically: The high-speed airflow in the air inlet first enters the cooling channel through the leading edge opening, and further contacts the cooling fins to achieve heat exchange cooling. The cooling fins will be deflected under the impact of the high-speed airflow, allowing the high-speed airflow to pass through the cooling channel smoothly. When the high-speed airflow moves to the outlet side of the cooling channel, a three-way flow split will be formed, two of which will enter the jet side channel through the opened lateral flow regulating splitter plate, and finally ejected from the airfoil jet bracket on the outlet side of the jet side channel. At this time, the cooling medium droplets ejected from the jet nozzle will be on the jet side. The airflow ejected from the channel increases the spanwise velocity to enhance the uniformity of cooling medium droplet diffusion. At the same time, the cooling medium droplets ejected in opposite directions from adjacent airfoil jet supports collide to reduce the particle size of the cooling medium droplets, thereby further improving the jet precooling effect. For the last of the three-way diversions, it will enter the jet tail channel through the opened trailing edge flow regulating diverter plate, and finally eject the airfoil jet support through the outlet side of the jet tail channel to reduce the backflow at the trailing edge and further suppress the generation of uneven wakes.

Images