A self-driven flap thermal cutoff design method

Abstract

The present application belongs to the technical field of aircraft heat protection, and relates to a self-driven cowl heat blocking design method. The method is provided with a channel, an inner cavity and a small hole structure inside the cowl. The channel entrance is usually arranged on the bottom surface or side surface of the cowl. The channel spirally rises in the cowl, and the channel exit is connected with the inner cavity of the cowl. The working medium reaches the inner cavity of the cowl through the channel. A plurality of small holes are arranged on the top surface of the cowl. The bottom of each small hole is connected with the inner cavity of the cowl, and the working medium flows out of each small hole. A one-way valve is arranged on the channel connecting the storage tank and the channel entrance. The one-way valve is initially in a closed state, and is opened when the pressure difference between the two sides reaches a preset value. The storage tank is arranged in the aircraft. A pressure increasing device is connected with the storage tank, and is used for pushing the working medium to flow under the action of the pressure difference between the inside and outside of the aircraft. The method of the present application uses a self-cooling heat protection mode to utilize the fact that the internal air pressure of the aircraft is higher than the external air pressure at high altitudes, so as to realize self-driven heat blocking and control the environmental temperature of the temperature-sensitive devices in the aircraft.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aircraft heat protection, and particularly relates to a design method of aircraft heat blocking technology. BACKGROUND

[0002] During the flight of the aircraft in the high altitude, the incoming air is subjected to strong compression and friction, which will cause serious aerodynamic heating, so that the surface temperature of the aircraft rises sharply. With the increase of flight time, the aerodynamic heating gradually accumulates, and the heat is further transmitted along the aircraft shell to the inside, causing the temperature of the internal environment of the aircraft to rise, which will cause the destruction of the temperature-sensitive devices and cause the failure of the flight mission if the temperature of the temperature-sensitive devices exceeds the use temperature.

[0003] In order to avoid the high temperature of the internal environment of the aircraft, the existing scheme mainly adopts the passive heat protection mode, however, the passive heat protection scheme needs to select the appropriate thickness of the heat protection layer when the flight environment changes, and the local temperature control effect is limited in a small range, which is difficult to apply to high-speed long-endurance flight missions. In addition, in the case that there is a gap between the protruding parts of the aircraft and the fuselage, due to the effect of the gap flow, the local thermal environment is deteriorated, and more serious ablation will occur in the airflow, further increasing the demand for heat protection and heat insulation. Therefore, it is necessary to carry out heat protection research on the local high-temperature environment. SUMMARY

[0004] In view of the heat protection demand of the local high-temperature environment of the aircraft, the present application proposes a self-driven flap heat blocking design method, which adopts a self-cooling mode to use the pressure difference between the inside and outside of the aircraft to transport the working medium to the flap, so as to realize self-driven heat blocking to prevent heat from being transmitted to the inside and control the environmental temperature of the temperature-sensitive device.

[0005] The technical scheme adopted by the present application is as follows:

[0006] The present invention proposes a self-driven thermal blocking design method for a cover, comprising: a channel 3, an inner cavity 12, and a small hole 11 structure are provided inside the cover 2, wherein the channel 3 is a flow channel for the working medium 7, the inlet of the channel 3 is usually arranged on the bottom surface or side of the cover 2, the channel 3 spirally rises inside the cover 2, and the outlet of the channel 3 is connected to the inner cavity 12 of the cover; the inner cavity 12 of the cover is a hollow structure arranged inside the cover 2, and the working medium 7 reaches the inner cavity 12 of the cover through the channel 3; a plurality of small holes 11 are arranged on the top surface of the cover 2, and the bottom of each small hole 11 is connected to the inner cavity 12 of the cover. The working fluid 7 flows out of each small hole 11 within the opening 12. The connecting shaft 4 passes through the opening 2 and is connected to the protruding member 1. A one-way valve 6 is provided in the passage connecting the storage box 9 and the entrance of the passage 3. It is a switch for the flow of the working fluid 7 and is initially closed. It opens when the pressure difference between the two sides reaches a preset value. The storage box 9 is provided inside the aircraft to store the working fluid 7. A pressurizing device 8 is connected to the storage box 9 and promotes the flow of the working fluid 7 under the action of the pressure difference between the inside and outside of the aircraft. A temperature-sensitive device 5 is provided inside the aircraft and connected to the lower end of the connecting shaft 4.

[0007] On the ground, the air pressure inside the cover 2 is almost equal to the external air pressure, the one-way valve 6 is closed, and the working medium 7 does not flow; in the air at high altitude, the internal pressure of the cover 2 is higher than the external air pressure, the pressure difference on both sides of the one-way valve 6 reaches a preset value, the one-way valve 6 opens, and under the action of the internal and external pressure difference, the booster device 8 pushes the working medium 7 in the storage box 9 to flow through the channel 3 and the inner cavity 12 of the cover in turn, fully absorbing the heat near the cover 2 and the connecting shaft 4, blocking the heat from transferring inward, and controlling the ambient temperature of the temperature-sensitive device 5; finally, the working medium 7 flows out from the small hole 11, further taking away the heat of the nearby air.

[0008] The protruding parts are usually structural or functional parts outside the shell, such as rudders, etc. The gap between them and the shell is a high-temperature environment, and the heat is conducted to the interior of the aircraft through the cover and the connecting shaft;

[0009] The flap has a channel, inner cavity, and small hole structure, which are designed as an integral part of the flap. The channel is the flow channel for the working medium, which flows in from the bottom or side of the flap. The cross-sectional shape of the channel is usually a regular shape such as a circle, triangle, quadrilateral, or ellipse. When the cross-sectional shape of the channel 3 is a triangle or quadrilateral, the adjacent surfaces of the channel are chamfered or non-chamfered. The channel outlet is the inner cavity of the flap; the inner cavity is the hollow structure inside the flap, and the working medium passes through the channel to reach the inner cavity. The small hole is arranged on the top surface of the flap, and the bottom of the small hole connects to the inner cavity, serving as the outlet for the working medium to flow out. The small hole shape is usually a regular shape such as a circle, triangle, quadrilateral, or ellipse.

[0010] The connecting shaft passes through the cover and is connected to the protruding component to bear / transmit force and heat;

[0011] The one-way valve is a switch for the flow of working fluid, which is initially closed and opens when the pressure difference between the two sides reaches a preset value;

[0012] The storage box is in the aircraft, and can be designed according to the effective space in the aircraft, and is used for storing the working medium;

[0013] The pressurizing device is connected with the storage box, and the working medium is pushed to flow under the action of the pressure difference between the inside and outside of the aircraft;

[0014] The working medium is a flowable medium which can take away the heat of the heated part, and under the action of the pressure difference between the inside and outside of the aircraft, sequentially enters the channel and the inner cavity from the storage box, absorbs the heat of the cover and the connecting shaft, and finally flows out from the small hole, further taking away the heat of the surrounding air; the working medium can be gas, liquid, supercritical fluid, etc.

[0015] The temperature-sensitive device is in the aircraft, and is an instrument protected by the thermal blocking design method, and the environmental temperature of the temperature-sensitive device is controlled under the action of the thermal blocking.

[0016] The core of the present application is to provide a self-driven cover thermal blocking design method, adopt a self-cooling thermal protection method, utilize the fact that the internal air pressure of the aircraft is higher than the external air pressure in the high altitude, realize self-driven blocking of the heat transfer to the inside, and control the environmental temperature of the temperature-sensitive device in the aircraft.

[0017] The self-driven cover thermal blocking principle of the present application is as follows:

[0018] Firstly, on the ground, the internal air pressure of the cover is almost equal to the external air pressure, and the one-way valve is closed.

[0019] Secondly, in the high altitude, the internal pressure of the cover is higher than the external air pressure, the pressure difference between the two sides of the one-way valve reaches a preset value, and the one-way valve is opened.

[0020] Subsequently, the working medium in the storage box is pushed to flow into the inner cavity through the channel under the action of the internal and external pressure difference, fully absorbs the heat near the cover and the connecting shaft, blocks the heat transfer to the inside, controls the environmental temperature of the temperature-sensitive device, and realizes self-driven blocking of the heat transfer to the inside.

[0021] Finally, the working medium flows out from the small hole, further taking away the heat of the surrounding air.

[0022] The present application has the beneficial effects that the self-driven cover thermal blocking design method provided by the embodiments of the present application adopts a self-cooling thermal protection method, utilizes the air pressure difference between the inside and outside of the cover to transport the working medium to the cover, realizes self-driven blocking of the heat transfer to the inside, and achieves the purpose of controlling the environmental temperature of the temperature-sensitive device. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the principle of the self-driven cover thermal blocking design method provided by the embodiments of the present application.

[0024] Figure 2is a schematic view of the cover structure.

[0025] Fig. 1: protruding part, 2: cover, 3: channel, 4: connecting shaft, 5: temperature-sensitive device, 6: one-way valve, 7: working medium, 8: pressure increasing device, 9: storage tank, 10: shell, 11: small hole, 12: inner cavity. DETAILED DESCRIPTION

[0026] The application will be further described below in conjunction with the drawings and specific embodiments.

[0027] The application relates to the field of high-speed aircraft heat protection, and particularly relates to a self-driven cover heat blocking design method.The application adopts a self-cooling heat protection mode, utilizes the fact that the internal air pressure of the aircraft is higher than the external air pressure in the high altitude, realizes self-driven heat blocking to the inside, and controls the environment temperature of the temperature-sensitive device inside the aircraft.

[0028] The arrangement mode is shown in Figs. 1-3, and specifically, the protruding part 1 is a structure or functional part outside the shell 10, and the gap between the protruding part 1 and the shell 10 is a high-temperature environment. Figure 1 Figure 2 The heat is conducted to the inside of the aircraft through the cover 2 and the connecting shaft 4.

[0029] Specifically, the cover 2 is internally provided with a channel 3, an inner cavity 12 and a small hole 11 structure, and is integrally designed with the cover 2, wherein the channel 3 is a flow channel of the working medium 7, the channel 3 inlet is usually arranged on the bottom surface or the side surface of the cover 2, the channel 3 cross section shape is usually a regular shape such as a circle, a triangle, a quadrilateral or an ellipse, when the channel 3 cross section shape is a triangle or a quadrilateral, the adjacent surfaces of the channel 3 are designed with a chamfer or without a chamfer. The channel 3 spirally rises in the cover 2, the channel 3 outlet is connected with the cover inner cavity 12, and the channel 3 route and cross section size are designed according to the cover 2 shape and the thermal environment; the cover inner cavity 12 is a hollow structure arranged inside the cover 2, and the working medium 7 reaches the cover inner cavity 12 through the channel 3; a plurality of small holes 11 are arranged on the top surface of the cover 2, the bottom of each small hole 11 is connected with the cover inner cavity 12, the working medium 7 flows out from each small hole 11, and the small hole 11 shape is usually a regular shape such as a circle, a triangle, a quadrilateral or an ellipse, and the number and distribution position of the small holes 11 are comprehensively considered according to the cover 2 shape and the thermal environment.

[0030] Specifically, the connecting shaft 4 is connected with the protruding part 1 after penetrating through the cover 2, and plays a role of bearing / transmitting force and heat;

[0031] Specifically, the one-way valve 6 is arranged on the channel connecting the storage tank 9 and the channel 3 inlet, and serves as an on-off switch for the working medium 7 flow, and is initially in a closed state, and is opened when the pressure difference between the two sides reaches a preset value;

[0032] Specifically, the storage tank 9 is arranged inside the aircraft, can be designed in a shape according to the effective space inside the aircraft, and is used for storing the working medium 7.

[0033] Specifically, the booster 8 is connected with the storage tank 9, and the working medium 7 is pushed to flow under the action of the pressure difference between the inside and outside of the aircraft;

[0034] Specifically, the working medium 7 is a substance that can take away the heat of the heated part, and under the action of the pressure difference between the inside and outside of the aircraft, sequentially enters the channel 3 and the inner cavity 12 from the storage tank 9, absorbs the heat of the cover 2 and the connecting shaft 4, and finally flows out from the small hole 11, further taking away the heat of the surrounding air;

[0035] Specifically, the temperature-sensitive device 5 is arranged inside the aircraft and connected with the lower end of the connecting shaft 4, and is an instrument protected by the thermal blocking design method, and the ambient temperature of the temperature-sensitive device 5 is controlled under the action of thermal blocking.

[0036] The self-driven thermal blocking design method of the cover of the application has the self-driven thermal blocking principle as follows:

[0037] Specifically, the gap between the protruding part 1 and the shell 10 is a high-temperature environment, and the heat is conducted to the inside of the aircraft through the cover 2 and the connecting shaft 4; on the ground, the internal pressure of the cover 2 is almost equal to the external pressure, the one-way valve 6 is closed, and the working medium 7 does not flow; in the high altitude, the internal pressure of the cover 2 is higher than the external pressure, the pressure difference between the two sides of the one-way valve 6 reaches a preset value, the one-way valve 6 is opened, and under the action of the internal and external pressure difference, the booster 8 pushes the working medium 7 in the storage tank 9 to flow through the channel 3 and the inner cavity 12 of the cover in turn, fully absorbs the heat near the cover 2 and the connecting shaft 4, blocks the heat conduction to the inside, and controls the ambient temperature of the temperature-sensitive device 5; finally, the working medium 7 flows out from the small hole 11, further taking away the heat of the surrounding air.

[0038] Specifically, the storage tank 9 and the booster 8 can be designed integrally, or other deformed containers can be selected.

[0039] Specifically, the working medium 7 can be gas, liquid, supercritical fluid, etc.

[0040] Specifically, the running time t of the cooling system at a certain flight height can be calculated by the following formula.

[0041]

[0042] Svt

[0043] In the above formula, P1 is the internal pressure of the cover, P0 is the external pressure of the cover, P m is the pressure drop generated by the one-way valve and the channel, ρ is the density of the working medium, ν is the flow rate of the working medium, V is the volume of the working medium in the storage tank, and S is the cross-sectional area of the channel.

[0044] The self-driven port cover thermal blocking design method provided by the embodiment of the application adopts a self-cooling thermal protection mode, uses the internal and external pressure difference to deliver the working medium to the port cover, realizes self-driven blocking of heat transfer to the inside, and achieves the purpose of environment temperature control of the temperature-sensitive device.

[0045] The above examples are only used to illustrate the technical method of the application but not to limit it. Although the application is described in detail with reference to the best embodiment, those skilled in the art should understand that the technical method of the application can still be modified or replaced equivalently, and these modifications or equivalent replacements cannot make the modified technical method deviate from the spirit and scope of the technical method of the application.

Claims

1. A self-actuated thermal blocking design method for a flap, characterized in that: include: The cover (2) is provided with a channel (3), an inner cavity (12) and a small hole (11) structure, wherein the channel (3) is a flow channel for the working medium (7), the inlet of the channel (3) is usually arranged on the bottom surface or the side surface of the cover (2), the channel (3) spirally rises in the cover (2), and the outlet of the channel (3) is connected to the inner cavity (12) of the cover; the inner cavity (12) of the cover is a hollow structure arranged inside the cover (2), and the working medium (7) reaches the inner cavity (12) of the cover through the channel (3); a plurality of small holes (11) are arranged on the cover ( 2) On the top surface, the bottom of each small hole (11) is connected to the inner cavity (12) of the opening cover, and the working medium (7) flows out from each small hole (11); a one-way valve (6) is provided on the channel connecting the storage box (9) and the inlet of the channel (3), and is a switch for the flow of the working medium (7), and is initially in a closed state and is opened when the pressure difference between the two sides reaches a preset value; the storage box (9) is provided in the aircraft and is used to store the working medium (7); the boosting device (8) is connected to the storage box (9), and promotes the flow of the working medium (7) under the action of the pressure difference between the inside and outside of the aircraft; On the ground, the air pressure inside the cover (2) is almost equal to the external air pressure, the one-way valve (6) is closed, and the working medium (7) does not flow; in the air, the pressure inside the cover (2) is higher than the external air pressure, the pressure difference on both sides of the one-way valve (6) reaches a preset value, the one-way valve (6) opens, and under the action of the internal and external pressure difference, the booster device (8) pushes the working medium (7) in the storage box (9) to flow through the channel (3) and the inner cavity of the cover (12) in turn, fully absorbing the heat near the cover (2) and the connecting shaft (4), blocking the heat transfer inward, and controlling the ambient temperature of the temperature-sensitive device (5); finally, the working medium (7) flows out from the small hole (11), further taking away the heat of the nearby air.

2. A self-actuated flap thermal blocking design method as claimed in claim 1, characterized in that: The cross-sectional shape of the channel (3) is a regular circular, triangular, quadrilateral or elliptical shape.

3. A self-actuated flap thermal blocking design method as claimed in claim 2, characterized in that: When the cross-sectional shape of the channel (3) is a triangle or a quadrilateral, adjacent surfaces of the channel are designed with chamfers or without chamfers.

4. A self-actuated flap thermal blocking design method as claimed in claim 3, characterized in that: The route and cross-sectional size of channel 3 are designed based on the shape of the cover (2) and the thermal environment.

5. A self-actuated flap thermal blocking design method as claimed in claim 1, characterized in that: The small hole (11) is in the shape of a circle, triangle, quadrilateral or ellipse.

6. A self-actuated flap thermal blocking design method as claimed in claim 5, characterized in that: The number and distribution of the small holes (11) are comprehensively considered based on the shape of the cover (2) and the thermal environment.

7. A self-actuated flap thermal blocking design method as claimed in claim 1, characterized in that: The storage box (9) and the pressure boosting device (8) can be designed as an integrated whole.

8. A self-actuated flap thermal blocking design method as claimed in claim 1, characterized in that: The working medium (7) can be gas, liquid or supercritical fluid.

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