Method for reducing surface heat of hypersonic vehicle by using acoustic impedance

Abstract

The present application discloses a method for hypersonic aircraft to achieve surface heat reduction by using acoustic impedance. The method includes: obtaining the attribute information of unstable waves formed in the surface area of ​​the aircraft during the flight of the aircraft, wherein the unstable wave is an atmospheric fluctuation whose amplitude increases with time or whose total energy increases with the consumption of the energy of the surrounding environment; determining the boundary parameters of the aircraft during the flight according to the attribute information of the unstable wave; determining the parameter information of the porous material laid on the surface area according to the boundary parameters, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion pressure wave in the acoustic wave passing through the acoustic waveguide meets the preset conditions. The present application solves the technical problem that the method of using low thermal conductivity materials for insulation or using cooling fluid heat exchange to achieve heat reduction has a large weight.

Description

Technical Field

[0001] The present application relates to the field of acoustics, and in particular, to a method for reducing surface heat of a hypersonic vehicle by utilizing acoustic impedance. Background Art

[0002] The thermal protection systems of hypersonic vehicles are divided into two categories: active thermal protection systems and passive thermal protection systems. Active thermal protection systems include a variety of thermal protection structures and methods, such as commonly used thermal insulation structures, heat shielding structures, film cooling structures, regenerative cooling structures, heat pipe structures, etc. Passive thermal protection systems use a variety of polymer and composite thermal protection coatings with good ablative properties to ensure that the aircraft is not damaged by strong heat flow.

[0003] The basic principle is based on the traditional heat and mass transfer principle, that is, using low thermal conductivity materials for insulation or using cooling fluid heat exchange to achieve heat reduction (such as commonly used insulation structure, heat shielding structure, film cooling structure, regenerative cooling structure, heat pipe structure, composite material thermal protection coating) or using disposable ablative materials for short-term heat reduction. The materials used in this method have the problems of heavy weight and complex structure.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiment of the present application provides a method for reducing surface heat of a hypersonic vehicle by using acoustic impedance, so as to at least solve the technical problem that the method of using low thermal conductivity materials for insulation or using cooling fluid heat exchange to reduce heat has high weight.

[0006] According to one aspect of an embodiment of the present application, a method for realizing surface cooling of a hypersonic aircraft by using acoustic impedance is provided, comprising: obtaining attribute information of unstable waves formed in a surface area of ​​an aircraft during flight, wherein the unstable waves are atmospheric fluctuations whose amplitude increases with time or whose total energy increases with the consumption of energy in the surrounding environment; determining boundary parameters of the aircraft during flight based on the attribute information of the unstable waves; determining parameter information of a porous material laid on the surface area based on the boundary parameters, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the acoustic waveguide meets a preset condition.

[0007] Optionally, boundary parameters of the aircraft during flight are determined based on attribute information of unstable waves, including: obtaining the frequency of unstable waves corresponding to the current environment; determining the boundary parameters based on a relationship curve between the boundary parameters and the frequency of unstable waves, and the frequency of unstable waves corresponding to the current environment.

[0008] Optionally, the parameter information of the porous material includes at least material properties of the porous material.

[0009] Optionally, the method further includes: determining a laying position of the porous material according to material properties and boundary parameters of the porous material.

[0010] Optionally, the boundary parameter is acoustic impedance.

[0011] Optionally, the preset condition is that the cosine value of the phase between the pressure wave and the expansion wave is greater than 0.

[0012] Optionally, the attribute information of the unstable wave includes at least the frequency of the unstable wave and the growth rate of the unstable wave.

[0013] Optionally, the porous material is made of fine-grained spherical powder stainless steel by high-temperature sintering.

[0014] According to another aspect of an embodiment of the present application, there is also provided an aircraft, comprising: a fuselage and a porous material coating laid on the surface of the fuselage, wherein parameter information of the coating satisfies the following conditions: after the porous material is laid on the surface of the aircraft, an acoustic waveguide is formed on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the acoustic waveguide satisfies a preset condition.

[0015] According to another aspect of the embodiment of the present application, there is also provided an electronic device, comprising: a memory for storing program instructions; a processor, connected to the memory, for executing program instructions to implement the following functions: obtaining property information of unstable waves formed in a surface area of ​​an aircraft during flight, wherein the unstable waves are atmospheric fluctuations whose amplitude increases with time or whose total energy increases with the consumption of surrounding environment energy; determining boundary parameters of the aircraft during flight based on the property information of the unstable waves; determining parameter information of a porous material laid on the surface area based on the boundary parameters, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the acoustic waveguide meets a preset condition.

[0016] According to another aspect of an embodiment of the present application, a non-volatile storage medium is provided, which includes a storage medium, wherein when a program is running, a device where the non-volatile storage medium is located is controlled to execute the above-mentioned method of using acoustic impedance to achieve surface cooling for a hypersonic aircraft.

[0017] In an embodiment of the present application, by obtaining the attribute information of unstable waves formed in the surface area of ​​the aircraft during the flight, the boundary parameters of the aircraft during the flight are determined based on the attribute information of the unstable waves, and based on the boundary parameters, the parameter information of the porous material laid on the surface area is determined, thereby achieving the purpose of determining the parameter information of the porous material based on the attribute information of the unstable wave, thereby achieving the technical effect of laying the porous material on the surface of the aircraft to achieve heat reduction, and further solving the technical problem of heavy weight in the method of using low thermal conductivity materials for insulation or using cooling fluid heat exchange to achieve heat reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0019] Figure 1 It is a hardware structure block diagram of a computer terminal (or electronic device) for a method for realizing surface heat reduction of a hypersonic aircraft by using acoustic impedance according to an embodiment of the present application;

[0020] Figure 2 is a flow chart of a method for realizing surface heat reduction of a hypersonic vehicle by using acoustic impedance according to an embodiment of the present application;

[0021] Figure 3 is a microscope image of a wind tunnel model and a surface porous material according to an embodiment of the present application;

[0022] Figure 4 It is a comparison chart of the heat flow variation over time of a common smooth surface model and a porous material surface according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] The related technology is based on the basic principle of traditional heat and mass transfer, that is, the method of using low thermal conductivity materials for insulation or using cooling fluid heat exchange to achieve heat reduction (insulation structure, heat shielding structure, film cooling structure, regenerative cooling structure, heat pipe structure, composite material thermal protection coating). This material often has the problems of heavy weight and complex structure, and the material is a disposable ablative material and cannot be used repeatedly. In order to solve the above technical problems, the embodiments of the present application provide corresponding solutions, which are described in detail below.

[0026] The method embodiment of the hypersonic aircraft using acoustic impedance to achieve surface heat reduction provided in the embodiment of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Figure 1 The hardware structure block diagram of a computer terminal (or electronic device) for implementing a method for reducing surface heat of a hypersonic vehicle by using acoustic impedance is shown. Figure 1 As shown, the computer terminal 10 (or electronic device 10) may include one or more (102a, 102b, ..., 102n are used to illustrate) processors (the processor may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 104 for storing data, and a transmission module 106 for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0027] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computer terminal 10 (or electronic device). As described in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0028] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the method for realizing surface heat reduction by using acoustic impedance for a hypersonic aircraft in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, that is, realizing the method for realizing surface heat reduction by using acoustic impedance for a hypersonic aircraft. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 104 may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer terminal 10 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0029] The transmission module 106 is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the computer terminal 10. In one example, the transmission device 106 includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0030] The display may be, for example, a touch screen liquid crystal display (LCD) that enables a user to interact with a user interface of the computer terminal 10 (or electronic device).

[0031] It should be noted that, in some optional embodiments, the above Figure 1 The computer device (or electronic device) shown may include hardware elements (including circuits), software elements (including computer code stored on a computer-readable medium), or a combination of hardware elements and software elements. It should be noted that Figure 1This is merely one example of a particular embodiment and is intended to illustrate the types of components that may be present in the above-described computer device (or electronic device).

[0032] In the above operating environment, an embodiment of the present application provides an embodiment of a method for realizing surface cooling of a hypersonic aircraft by using acoustic impedance. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] Figure 2 is a flow chart of a method for realizing surface heat reduction of a hypersonic aircraft using acoustic impedance according to an embodiment of the present application, which is used to determine parameter information of materials laid on the surface of the aircraft, thereby realizing heat reduction in high-speed airflow based on the thermoacoustic principle, such as Figure 2 As shown, the method comprises the following steps:

[0034] Step S202, obtaining attribute information of unstable waves formed on the surface area of ​​the aircraft during the flight of the aircraft, wherein the unstable wave is an atmospheric fluctuation whose amplitude increases with time or whose total energy increases with the consumption of surrounding environment energy;

[0035] Step S204, determining the boundary parameters of the aircraft during flight according to the attribute information of the unstable wave;

[0036] Step S206, determining parameter information of the porous material laid on the surface area based on the boundary parameters, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the acoustic waveguide meets the preset conditions.

[0037] In the above steps S202 to S206, by arranging porous materials on the surface of the aircraft, the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the porous material can be modified, thereby achieving heat reduction of the aircraft.

[0038] When an aircraft flies in a high-speed airflow, the hypersonic flow will automatically form an acoustic waveguide on the surface of the aircraft. A second mode wave acoustic disturbance will appear in the acoustic waveguide, and its compression and expansion process will bring about a thermal effect. The heat absorption or heat release process of the device is determined by the phase difference between the pressure wave and the expansion wave inside the acoustic wave. Specifically, the preset condition is that when the cosine value of the phase difference between the pressure wave and the expansion wave is less than 0, heat is released; when the cosine value of the phase difference between the pressure wave and the expansion wave is greater than 0, heat is absorbed.

[0039] It should be noted that the second mode wave is an unstable wave unique to hypersonic wall flow. Its manifestation is similar to that of sound waves and it is mainly transmitted in the form of sound waves near the wall.

[0040] Since it is necessary to determine the boundary parameters based on the stability theory when determining the material parameters, in step S204 of the above-mentioned material parameter determination method, the boundary parameters of the aircraft during flight are determined based on the attribute information of the unstable wave, which specifically includes the following steps: obtaining the frequency of the unstable wave corresponding to the current environment; determining the boundary parameters based on the relationship curve between the boundary parameters and the frequency of the unstable wave, and the frequency of the unstable wave corresponding to the current environment.

[0041] In the above steps, the frequency, growth rate and other attribute information of the unstable wave in the flow under different boundary parameters can be given according to the stability theory, and the acoustic impedance is one of the boundary parameters. The boundary parameter in the embodiment of the present application mainly refers to the acoustic impedance of the material, and the acoustic impedance refers to the ratio of the pressure pulsation amplitude to the velocity pulsation amplitude at the boundary (material surface). For example, by inputting different acoustic impedance values, a curve of the relationship between the acoustic impedance and the unstable wave frequency can be obtained according to the stability theory, and the frequency of the unstable wave can be measured in the experiment, so as to obtain the corresponding acoustic impedance in reverse.

[0042] At the same time, according to the typical acoustic material formula (such as multi-layer perforated plate), the relationship between the geometric parameters, material properties and acoustic impedance of the acoustic material is given. Under the premise of known acoustic impedance and material acoustic properties, the geometric parameters of the porous material can be inferred.

[0043] Through the above description, based on the stability theory analysis, the acoustic impedance size and laying position that meet the requirements are obtained, and according to the acoustic impedance information, fine-grained spherical powder stainless steel is used to form a metal porous material through high-temperature sintering, and the porous material is laid on the surface of the aircraft to form acoustic impedance.

[0044] In an embodiment of the present application, the parameter information of the porous material includes at least the material properties of the porous material, where the properties of the porous material include at least the acoustic impedance information corresponding to the material, and the laying position of the porous material is determined based on the material properties of the porous material and the boundary parameters, wherein the laying position is the position where the porous material is laid on the surface of the aircraft.

[0045] The position for laying the porous material can be obtained in the following manner: using a high-frequency pressure sensor to measure the disturbance amplitude at different positions on a smooth surface without the porous material installed, and selecting the position with the maximum disturbance amplitude as the position for laying the porous material.

[0046] An embodiment of the present application also provides an aircraft, specifically comprising: a fuselage and a porous material coating laid on the surface of the fuselage, wherein parameter information of the coating satisfies the following conditions: after the porous material is laid on the surface of the aircraft, an acoustic waveguide is formed on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the sound wave passing through the acoustic waveguide satisfies a preset condition.

[0047] It should be noted that the method for determining the parameters of the porous material coating on the surface of the aircraft in the embodiment of the present application and Figure 2 The method for achieving surface cooling using acoustic impedance in the hypersonic aircraft shown is the same. The relevant explanations in the above-mentioned method for achieving surface cooling using acoustic impedance in the hypersonic aircraft are also applicable to the determination of the parameters of the porous material coating on the surface of the aircraft, and will not be repeated here.

[0048] Figure 3 is a microscope image of a wind tunnel model and a surface porous material according to an embodiment of the present application, such as Figure 3 As shown, Figure 3 The wind tunnel model on the left is 260mm in total length. The front 100mm is a straight cone with a semi-apex angle of 5 degrees, and the rear 160mm is a skirt cone with a tangent arc with a radius of 935mm. Figure 3 The right side is a magnified microscope image of the surface porous material, where the average pore size of the porous material is 0.1 mm. Figure 3 The wind tunnel model shown is used to simulate the heat flux changes on the surface of the aircraft in a hypersonic environment. The experimental results are shown in Figure 4 As shown, Figure 4 This is a comparison chart of heat flux variation over time between an ordinary smooth surface model and a porous material surface. It should be noted that the ordinary smooth surface is achieved by attaching a layer of copper foil with a thickness of 0.1 mm on the surface of the porous material. Figure 4 The results show that in the same high-speed flow, the heat flux of porous materials decreases by about 25% compared to smooth surface materials.

[0049] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0050] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0051] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0052] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0053] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0054] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0055] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for reducing surface heat of a hypersonic vehicle by using acoustic impedance, characterized in that: include: Acquiring attribute information of unstable waves formed on the surface area of ​​the aircraft during the flight of the aircraft, wherein the unstable waves are atmospheric fluctuations whose amplitude increases with time or whose total energy increases with the consumption of surrounding environment energy; Determining boundary parameters of the aircraft during flight according to the attribute information of the unstable wave; Determining parameter information of a porous material laid on the surface area according to the boundary parameter, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the acoustic wave passing through the acoustic waveguide meets a preset condition, the parameter information of the porous material at least includes the material properties of the porous material, and the boundary parameter is the acoustic impedance; Determining the boundary parameters of the aircraft during flight according to the attribute information of the unstable wave includes: obtaining the frequency of the unstable wave corresponding to the current environment; determining the boundary parameters according to a relationship curve between the boundary parameters and the frequency of the unstable wave, and the frequency of the unstable wave corresponding to the current environment.

2. The method according to claim 1, characterized in that The method further includes: determining a laying position of the porous material according to the material properties of the porous material and the boundary parameters.

3. The method according to claim 1, characterized in that The preset condition is that the cosine value of the phase between the pressure wave and the expansion wave is greater than 0.

4. The method according to claim 1, characterized in that: The attribute information of the unstable wave includes at least the frequency of the unstable wave and the growth rate of the unstable wave.

5. The method according to claim 1, characterized in that The porous material is made of fine-grained spherical powder stainless steel through high-temperature sintering.

6. An aircraft, characterized in that: include: A fuselage and a porous material coating laid on the surface of the fuselage, wherein parameter information of the coating is determined according to the method for achieving surface heat reduction by using acoustic impedance in a hypersonic aircraft as described in any one of claims 1 to 5.

7. An electronic device, characterized in that: include: A memory for storing program instructions; A processor is connected to the memory and is used to execute program instructions to implement the following functions: obtaining attribute information of unstable waves formed in the surface area of ​​the aircraft during the flight of the aircraft, wherein the unstable waves are atmospheric fluctuations whose amplitude increases with time or whose total energy increases with the consumption of energy in the surrounding environment; determining boundary parameters of the aircraft during the flight according to the attribute information of the unstable waves; determining parameter information of a porous material laid on the surface area according to the boundary parameters, wherein the parameter information is used to form an acoustic waveguide on the surface of the aircraft after the porous material is laid on the surface of the aircraft, and the phase relationship between the pressure wave and the expansion wave in the acoustic wave passing through the acoustic waveguide meets a preset condition, the parameter information of the porous material at least includes the material properties of the porous material, and the boundary parameter is acoustic impedance; determining the boundary parameters of the aircraft during the flight according to the attribute information of the unstable waves, including: obtaining the frequency of the unstable wave corresponding to the current environment; determining the boundary parameter according to a relationship curve between the boundary parameter and the frequency of the unstable wave, and the frequency of the unstable wave corresponding to the current environment.

8. A non-volatile storage medium, characterized in that: The non-volatile storage medium includes a stored program, wherein when the program is running, the device where the non-volatile storage medium is located is controlled to execute the method for realizing surface heat reduction of a hypersonic aircraft by using acoustic impedance as described in any one of claims 1 to 5.

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