Micro-jet active heat protection system for high-Mach-number aircraft

Abstract

According to the micro-jet active heat protection system for the high-Mach-number aircraft, a low-temperature propellant serves as a working medium and is coupled with an aircraft power system, and the working medium is stored and driven by means of a power system storage box and a booster pump, so that the weight cost of the active heat protection system is reduced to a great extent; the active heat protection system can meet the requirements of the limit heat protection capacity and the light heat protection scheme at the same time, and the engineering practicability of the active heat protection system on the high-Mach-number aircraft is guaranteed.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of active heat protection technology of high Mach number aircraft, and particularly relates to a micro-jet active heat protection system of high Mach number aircraft. BACKGROUND

[0002] High Mach number aircraft has important military value and is an important development direction in the field of aerospace. Countries such as the United States, Russia, the United Kingdom and Germany have actively carried out related research work, such as the X-43, X-51 of the United States, Yu-71 of Russia, "Cloud Tower" of the United Kingdom and SHEFEX2 of Germany. High Mach number aircraft usually adopts a passive heat protection scheme, which absorbs or radiates the heat transferred from the high-temperature air after the wave to the surface of the aircraft through heat protection structures and materials. With the increase of flight speed and cruising time, the aerodynamic heat flow level and total heat load level on the surface of the aircraft will rise, and the required structure weight of the passive heat protection scheme will rise significantly, which seriously affects the performance indicators of high Mach number aircraft. In extreme conditions, the aircraft may even be burned due to the fact that the temperature limit of the heat protection material cannot meet the heat protection ability requirement, resulting in the problem of "thermal barrier".

[0003] Due to the extremely high flight speed of high Mach number aircraft, the surface of the aircraft will be subjected to significant aerodynamic heating of high-temperature air after the wave. In order to prevent the structure material of the aircraft from being burned due to overheating, high Mach number aircraft is generally designed with passive heat protection, which prevents and insulates the external aerodynamic heat flow. With the continuous increase of flight speed and cruising time of high Mach number aircraft, the aerodynamic heating faced by the aircraft becomes more severe, and the temperature of the heat protection structure on the surface of the aircraft will also rise. In extreme conditions, the temperature resistance performance of the common heat protection material will not be able to meet the service temperature requirement, resulting in the problem that the heat protection design becomes a bottleneck problem limiting the development of high Mach number aircraft. The micro-jet active heat protection technology can play a good heat insulation and heat absorption effect by designing a corresponding micro-channel system in the typical high heat flow area of the aircraft and using the jet micro-hole to spray the cooling working medium to the outside, so it is an important technical approach to solve the extreme condition heat protection problem of high Mach number aircraft.

[0004] The micro-jet active heat protection technology is an important technical approach to solve the problem of "thermal barrier". The cooling working medium is sprayed into the flow field at a certain speed and angle through the wall opening, and the working medium flows downstream and forms a gas film structure covering a certain area of the wall, thereby playing a heat insulation and heat absorption effect. When the micro-jet scheme is used for active heat protection, the aircraft needs to carry additional cooling working medium, so a corresponding container is needed to store the working medium, and a pump or other device is needed to drive the cooling working medium to flow through the pipeline and finally sprayed out of the jet micro-hole. Therefore, the system has the disadvantage of large additional weight, which cannot well meet the requirements of "extreme heat protection ability and light heat protection scheme" at the same time. SUMMARY

[0005] In order to overcome the defects of the prior art, the application provides a high-Mach-number aircraft micro-jet active heat protection system, which uses low-temperature propellant as a working medium, is coupled with a power system, stores and drives the working medium by using a storage tank and a booster pump of the power system, and thus greatly reduces the weight cost of the active heat protection system, so that the active heat protection system meets the requirements of both the extreme heat protection capacity and the light heat protection scheme, and ensures the engineering practicability of the active heat protection system on the high-Mach-number aircraft.

[0006] The high-Mach-number aircraft micro-jet active heat protection system is coupled with a power system, the cooling working medium is stored in a storage tank of the power system, and the heat protection system comprises a turbine pump, a heat exchanger, a temperature sensor, a pressure sensor, a comprehensive controller, a main-path electromagnetic valve, a bypass valve, a jet micro-hole path and a direct discharge path.

[0007] When the heat protection system starts to work, liquid oxygen flows out of the storage tank and first enters the turbine pump to be pressurized; after being pressurized, the liquid oxygen flows through the heat exchanger to exchange heat with equipment in the cabin of the aircraft, and the liquid oxygen is converted into oxygen; the temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen at the outlet of the heat exchanger, and the measurement results are transmitted to the comprehensive controller; the comprehensive controller calculates the current state of the working medium according to the measurement results of the temperature and the pressure, and opens the main-path electromagnetic valve and the bypass valve after the state of the working medium is determined; the oxygen flows to the jet micro-hole path or the direct discharge path through the bypass valve.

[0008] The cooling working medium is liquid oxygen.

[0009] The jet micro-hole path is provided with a temperature sensor, a pressure sensor and a flow sensor, the temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen, and the measurement results are fed back to the comprehensive controller; the comprehensive controller calculates the amount of oxygen required for active heat protection in the high-heat-flow area according to the state parameters of the oxygen and the real-time measurement results of the flight conditions, compares the result with the measurement result of the flow sensor, adjusts the opening degree of the bypass valve, and discharges the excess oxygen to the outside through the direct discharge path.

[0010] Further, the jet micro-hole path is provided with multiple branches for flow distribution to the jet micro-holes, each branch corresponds to a regional jet micro-hole, and the branch is provided with a branch electromagnetic valve and a flow sensor for measuring the flow of each branch and feeding back the measurement result to the comprehensive controller; the comprehensive controller calculates the target opening degree of each branch according to the measurement results of the flows of the branches, sends instructions to the branch electromagnetic valves to control the opening degrees of the branches, and ensures the coordinated matching of the actual flows of the branches.

[0011] Further, the oxygen flows through the branches and is finally sprayed out of the regional jet micro-holes to form an air film on the surface of the high-heat-flow area of the aircraft, so as to actively protect the high-heat-flow area of the aircraft.

[0012] The beneficial effects of the present application are as follows:

[0013] (1) The active heat protection system proposed by the present application directly uses liquid oxygen as the cooling working medium, which can be directly coupled with the vehicle power system, and the storage and pressurization of the working medium can be completed by using the storage tank and turbine pump of the power system, thereby greatly reducing the weight cost of the active heat protection system and ensuring that the active heat protection system meets the requirements of both "extreme heat protection capability" and "lightweight heat protection scheme";

[0014] (2) The active heat protection system proposed by the present application uses the heat sink of liquid oxygen to cool the equipment in the vehicle cabin that generates a large amount of heat and has a relatively high temperature, ensuring that the temperature of the equipment in the cabin is within the normal range. After absorbing heat, the liquid oxygen is converted into oxygen, which is used for active heat protection of the vehicle in the subsequent process, so that the heat protection system has the functions of cabin heat control and external heat protection, realizing integrated heat management of the cabin and the outside;

[0015] (3) The active heat protection system proposed by the present application proposes a set of flow control logic, which measures and controls key parameters such as oxygen state, pipe opening degree, and oxygen flow rate by designing a comprehensive controller, valves, and sensors, so that the oxygen flowing out of the jet micro-hole from the high heat flow area is controllable and the flow is coordinated, ensuring that the system can achieve reliable active heat protection in complex and variable flight processes. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of a micro-jet active heat protection system of a high-Mach-number vehicle.

[0017] The blue lines in the figure represent the flow process of the working medium, the gray lines represent the signal input and output relationship between the comprehensive controller and the sensors, valves, and the red lines represent the heat generated by the equipment or the aerodynamic heat flow. DETAILED DESCRIPTION

[0018] The technical solutions of the present application will be further described in detail below in combination with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0019] As shown in Figure 1 A micro-jet active heat protection system of a high-Mach-number vehicle is coupled with a power system, and the cooling working medium liquid oxygen is directly stored in the storage tank of the power system. When the heat protection system starts to work, the liquid oxygen flows out of the storage tank and first enters the turbine pump for pressurization, ensuring that the working medium can overcome the pipe flow resistance and environmental back pressure, and finally flows out of the jet micro-hole.

[0020] After the liquid oxygen is pressurized, it flows through the heat exchanger to exchange heat with the equipment in the spacecraft cabin that generates a large amount of heat and has a high temperature, so that the heat generated by the equipment in the cabin is absorbed by the liquid oxygen as a heat sink to prevent the equipment in the cabin from overheating, and the liquid oxygen is phase changed from liquid oxygen to oxygen gas for subsequent micro-jet cooling;

[0021] After the liquid oxygen is changed into oxygen gas by the heat exchanger, the temperature and pressure sensors at the outlet of the heat exchanger measure the state parameters of the oxygen gas and transmit the measurement results to the integrated controller. The integrated controller calculates the current state of the working medium and obtains its position on the phase diagram based on the measurement results of the temperature and pressure, to ensure that the working medium is fully phase changed from liquid to gas.

[0022] After the state of the working medium is determined, the integrated controller opens the main electromagnetic valve and the bypass valve. The oxygen gas can flow to the jet micro-hole one-way or be directly discharged one-way. In the initial stage, the oxygen gas flows to the jet micro-hole one-way, which is equipped with temperature, pressure and flow sensors. The temperature and pressure sensors measure the state parameters of the oxygen gas and feed back the measurement results to the integrated controller. The integrated controller calculates the amount of oxygen gas required for active heat protection in the high heat flux area based on the state parameters (temperature and pressure) of the oxygen gas and the real-time measurement results (altitude, Mach number, angle of attack, side slip angle, etc.) of the flight conditions, and compares the calculated amount with the measurement results of the flow sensor. By adjusting the opening degree of the bypass valve, the excess oxygen gas is discharged to the outside through the directly discharged one-way, to ensure that the target flow calculated and the actual flow measured by the flow sensor match each other.

[0023] The oxygen gas in the jet micro-hole one-way downstream of the bypass valve is distributed to the jet micro-holes through multiple branch pipes, each of which corresponds to the jet micro-holes in a certain area. Electromagnetic valves and flow sensors are designed on the branch pipes to measure the flow of each branch and feed back the measurement results to the integrated controller. The integrated controller calculates the target opening degree of each branch based on the flow measurement results of each branch and sends instructions to the electromagnetic valves to control the opening degree of each branch, to ensure the coordinated matching of the actual flow of each branch.

[0024] The oxygen gas flows through each branch and is finally sprayed out of the jet micro-holes to form an air film on the surface of the high heat flux area of the aircraft, thereby actively protecting the high heat flux area of the aircraft and reducing the level of aerodynamic heat transferred to the surface of the aircraft.

[0025] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A micro-jet active heat protection system for a high Mach number aircraft, characterized in that, The cooling medium is stored in the power system and the heat protection system includes a turbine pump, a heat exchanger, a temperature sensor, a pressure sensor, a comprehensive controller, a main electromagnetic valve, a bypass valve, a jet micro-hole path and a direct discharge path. When the heat protection system starts to work, the liquid oxygen flows out of the storage tank and enters the turbine pump first to be pressurized. After being pressurized, the liquid oxygen flows through the heat exchanger to exchange heat with the equipment in the cabin of the aircraft, and the liquid oxygen is converted into oxygen. The temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen at the outlet of the heat exchanger, and the measurement results are transmitted to the comprehensive controller. The comprehensive controller calculates the current state of the working medium according to the measurement results of the temperature and the pressure, and opens the main electromagnetic valve and the bypass valve. The oxygen flows to the jet micro-hole path or the direct discharge path through the bypass valve.

2. A micro-jet active heat protection system for a high Mach number aircraft according to claim 1, wherein, The cooling medium is liquid oxygen.

3. A micro-jet active heat protection system for a high Mach number aircraft as recited in claim 1, characterized by, The jet micro-hole path is provided with a temperature sensor, a pressure sensor and a flow sensor. The temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen, and the measurement results are fed back to the comprehensive controller. The comprehensive controller calculates the amount of oxygen required for active heat protection in the high heat flux area according to the state parameters of the oxygen and the real-time measurement results of the flight conditions, and compares the measurement results with the measurement results of the flow sensor. The excess oxygen is discharged to the outside through the direct discharge path by adjusting the opening degree of the bypass valve.

4. A microfluidic active thermal protection system for a hypersonic vehicle according to claim 3, wherein, The jet micro-hole path is provided with a temperature sensor, a pressure sensor and a flow sensor. The temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen, and the measurement results are fed back to the comprehensive controller. The comprehensive controller calculates the amount of oxygen required for active heat protection in the high heat flux area according to the state parameters of the oxygen and the real-time measurement results of the flight conditions, and compares the measurement results with the measurement results of the flow sensor. The excess oxygen is discharged to the outside through the direct discharge path by adjusting the opening degree of the bypass valve.

5. A micro-jet active heat protection system for a high Mach number aircraft according to claim 4, wherein, The jet micro-hole path is provided with a temperature sensor, a pressure sensor and a flow sensor. The temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen, and the measurement results are fed back to the comprehensive controller. The comprehensive controller calculates the amount of oxygen required for active heat protection in the high heat flux area according to the state parameters of the oxygen and the real-time measurement results of the flight conditions, and compares the measurement results with the measurement results of the flow sensor. The excess oxygen is discharged to the outside through the direct discharge path by adjusting the opening degree of the bypass valve. The jet micro-hole path is provided with a temperature sensor, a pressure sensor and a flow sensor. The temperature sensor and the pressure sensor are used to measure the state parameters of the oxygen, and the measurement results are fed back to the comprehensive controller. The comprehensive controller calculates the amount of oxygen required for active heat protection in the high heat flux area according to the state parameters of the oxygen and the real-time measurement results of the flight conditions, and compares the measurement results with the measurement results of the flow sensor. The excess oxygen is discharged to the outside through the direct discharge path by adjusting the opening degree of the bypass valve.

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