A high-speed wind tunnel kilowatt-level microwave damage test device

Abstract

The present invention discloses a high-speed wind tunnel kilowatt-level microwave damage test device. A flat plate model is installed in the wind tunnel test section along the airflow, and a microwave source, a high-speed camera and an infrared thermal imager are installed outside the observation window on one side of the wind tunnel test section; the incident microwave emitted by the microwave source is fed into the wind tunnel test section through a circulator and a coupler in turn and irradiated on the surface of the flat plate model; a wave-transmitting glass is embedded in the center of the surface of the flat plate model, and other positions are coated with absorbing materials; a horn-shaped open waveguide is installed on the back of the wave-transmitting glass, and the open waveguide is closed on the directional coupler; an attenuator, a detector and an oscilloscope are installed on the other side outside the wind tunnel test section, and the oscilloscope is connected to a computer; at the same time, a front reflection microwave absorption plate array and a rear reflection microwave absorption plate array are installed in front and back of the flat plate model along the airflow direction. The device has a simple structure and can simulate the microwave temperature rise effect and microwave damage characteristics of the absorbing material under real flow field conditions in real time.

Description

Technical Field

[0001] The invention belongs to the technical field of high-speed wind tunnel tests, and in particular relates to a high-speed wind tunnel kilowatt-level microwave damage test device. Background Art

[0002] High-power microwave weapons are the nemesis of stealth fighters, which is mainly caused by the design characteristics of stealth fighters themselves. First of all, the stealth absorbing materials commonly used in stealth fighters include special graphite honeycomb materials and resin polymer materials. The working principle of "stealth materials" is to convert radar waves into heat energy and emit them to avoid reflection. At the same time, in order to further enhance the stealth effect, all stealth fighters are sprayed with a fairly thick layer of radar absorbing materials. The working principle of this absorbing material is basically the same as that of "stealth materials". Due to the large-scale use of absorbing materials, the US stealth fighters have good low detectability in front of radar. However, since most military radars currently work in the microwave band, stealth fighters can absorb a large amount of radar waves and microwaves, which creates its own fatal weakness and invites "self-destruction". The fourth-generation aircraft represented by the F22 mainly adopts stealth coating to achieve stealth. Stealth coating has some typical characteristics. First, it has a short life cycle and high maintenance cost. Second, the wave absorption performance drops sharply with the increase of temperature. Third, after local damage, the overall stealth performance of the whole aircraft drops sharply. For example, Andrew Lambert, former director of defense research of the British Royal Air Force, once said: Although Lockheed Martin has improved the stealth coating, a scratch can make the radar signal of the fighter the same as that of the 747. It is precisely because of the second and third characteristics that high-energy microwave weapons have significant advantages in anti-stealth coating. When a stealth fighter is irradiated by high-energy electromagnetic waves, the coating will generate high temperature due to excessive absorption of microwave energy, resulting in a decrease in stealth performance, or further causing cracks in the coating, damage to the appearance, etc., making its stealth capability ineffective.

[0003] With the successful development of solid-state high-power microwave systems, offensive microwave weapons have become possible. The sharp increase in microwave power can become a great threat to future aircraft. When high-power microwaves act on the surface of an aircraft, due to the reflection and diffraction of microwaves, a field enhancement effect is formed in the local area of ​​the aircraft. This effect causes a large amount of energy deposition, which interacts with the absorbing coating on the surface of the aircraft, causing deformation and changing its aerodynamic characteristics. In the process of studying microwave damage effects, many influencing factors are involved, among which the three key parameters are:

[0004] Sensitive frequency: determined by the characteristics of the target itself, and is the frequency point or frequency band to which it is sensitive.

[0005] Power threshold: below a certain power, no destructive effect will occur no matter how large the energy is.

[0006] Energy accumulation: Exceeding the power threshold must still have enough energy to destroy the target.

[0007] In the real flow field, the strong coupling effect between the velocity field and the temperature field will cause the change of the convective heat transfer coefficient in the heat conduction process, which will lead to drastic changes in the power threshold and energy accumulation of the target. Therefore, in order to evaluate the high-energy microwave damage effect of the real aircraft during high-speed flight, it is necessary to carry out microwave damage test research under real flow field conditions. Existing microwave tests are mainly carried out in open environments or microwave darkrooms, without considering the effects of convective heat transfer caused by real airflow.

[0008] Currently, there is an urgent need to develop a high-speed wind tunnel kilowatt-level microwave damage test device to simulate the impact of real airflow on microwave damage. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a high-speed wind tunnel kilowatt-level microwave damage test device.

[0010] The high-speed wind tunnel kilowatt-level microwave damage test device of the present invention is characterized in that a flat plate model is installed in the wind tunnel test section of the high-speed wind tunnel along the wind tunnel inflow and the airflow, a microwave source is installed outside the observation window on one side of the wind tunnel test section of the high-speed wind tunnel, and a high-speed camera and an infrared thermal imager are also installed; the incident microwave emitted by the microwave source is fed into the wind tunnel test section through a circulator and a coupler in sequence and then irradiated on the surface of the flat plate model; a wave-transmitting glass is embedded at the center of the surface of the flat plate model corresponding to the position of the incident microwave, and a wave-absorbing material is coated on the surface of the flat plate model avoiding the wave-transmitting glass, and the surface of the wave-transmitting glass and the surface of the wave-absorbing material are located on the same plane; a horn-shaped open waveguide is installed on the back of the wave-transmitting glass, the wave-transmitting glass and the open waveguide are sealed by a rubber ring, and the open waveguide is closed on a directional coupler; the cable of the directional coupler extends out of the wind tunnel test section and is sequentially connected to an attenuator, a detector, an oscilloscope and a computer located on the other side of the wind tunnel test section;

[0011] A high-temperature armored thermocouple is embedded in the edge of the flat plate model, and the distance between the high-temperature armored thermocouple and the surface of the flat plate model is 1 mm to 2 mm;

[0012] Along the wind tunnel flow, below the wind tunnel throat of the high-speed wind tunnel, a front reflection microwave absorption plate array is installed above the flat plate model, and a rear reflection microwave absorption plate array is installed below the flat plate model.

[0013] The incident area of ​​the incident microwave is greater than or equal to the surface area of ​​the flat plate model.

[0014] The material of the flat plate model is aluminum or steel.

[0015] The shape of the wave-transmitting glass is round or square.

[0016] The material of the wave-transmitting glass is quartz glass.

[0017] The material of the reflective microwave absorbing plates in the front reflective microwave absorbing plate array and the rear reflective microwave absorbing plate array is silicon carbide.

[0018] The opening diameter of the open waveguide is larger than the wavelength of the incident microwave.

[0019] The high-speed camera in the high-speed wind tunnel kilowatt-level microwave damage test device of the present invention is used to photograph the morphological changes of the absorbing material of the flat plate model, and the infrared thermal imager is used to measure the temperature rise effect of the absorbing material of the flat plate model.

[0020] The opening diameter of the open waveguide in the high-speed wind tunnel kilowatt-level microwave damage test device of the present invention is larger than the wavelength of the incident microwave, and the electric field parameters of the incident microwave can be accurately measured.

[0021] The high-speed wind tunnel kilowatt-level microwave damage test device of the present invention has a simple structure, can simulate in real time the microwave temperature rise effect and microwave damage characteristics of the absorbing material under the real flow field condition, and can more accurately obtain the parameters such as the power threshold and energy accumulation of the test absorbing material under the real flow field environment, providing an important basis for the scientific development and effective use of microwave weapons. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of the high-speed wind tunnel kilowatt-level microwave damage test device of the present invention.

[0023] In the figure, 1. microwave source 2. circulator 3. high-speed camera 4. infrared thermal imager 5. observation window 6. wind tunnel test section 7. wind tunnel throat 8. coupler 9. front reflection microwave absorption plate array 10. flat plate model 11. wave-transmitting glass 12. absorbing material 13. rear reflection microwave absorption plate array 14. high-temperature armored thermocouple 15. open waveguide 16. directional coupler 17. attenuator 18. detector 19. oscilloscope. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1

[0026] like Figure 1As shown, the flat plate model 10 of the high-speed wind tunnel kilowatt-level microwave damage test device of the present invention is installed in the wind tunnel test section 6 of the high-speed wind tunnel along the wind tunnel incoming flow and the airflow, and a microwave source 1 is installed outside the observation window 5 on one side of the wind tunnel test section 6 of the high-speed wind tunnel, and a high-speed camera 3 and an infrared thermal imager 4 are also installed; the incident microwave emitted by the microwave source 1 is fed into the wind tunnel test section 6 through the circulator 2 and the coupler 8 in sequence, and then irradiated on the surface of the flat plate model 10; a wave-transmitting glass 11 is embedded at the center of the surface of the flat plate model 10 corresponding to the position of the incident microwave, The absorbing material 12 is coated on the surface of the flat model 10 avoiding the wave-transmitting glass 11, and the surface of the wave-transmitting glass 11 and the surface of the absorbing material 12 are located on the same plane; a horn-shaped open waveguide 15 is installed on the back of the wave-transmitting glass 11, and the wave-transmitting glass 11 and the open waveguide 15 are sealed by a rubber ring, and the open waveguide 15 is closed on the directional coupler 16; the cable of the directional coupler 16 extends out of the wind tunnel test section 6 and is sequentially connected to the attenuator 17, the detector 18, the oscilloscope 19 and the computer located on the other side of the wind tunnel test section 6;

[0027] A high-temperature armored thermocouple 14 is embedded in the edge of the flat plate model 10, and the distance between the high-temperature armored thermocouple 14 and the surface of the flat plate model 10 is 1 mm to 2 mm;

[0028] Along the wind tunnel flow, below the wind tunnel throat 7 of the high-speed wind tunnel, a front reflection microwave absorption plate array 9 is installed above the flat plate model 10, and a rear reflection microwave absorption plate array 13 is installed below the flat plate model 10.

[0029] The incident area of ​​the incident microwave is greater than or equal to the surface area of ​​the flat plate model 10 .

[0030] The material of the flat plate model 10 is aluminum or steel.

[0031] The shape of the wave-transmitting glass 11 is circular or square.

[0032] The material of the wave-transmitting glass 11 is quartz glass.

[0033] The material of the reflective microwave absorbing plates in the front reflective microwave absorbing plate array 9 and the rear reflective microwave absorbing plate array 13 is silicon carbide.

[0034] The opening diameter of the open waveguide 15 is larger than the wavelength of the incident microwave.

[0035] The present invention is not limited to the above-mentioned specific implementation modes. Various changes made by technicians in the relevant technical field based on the above-mentioned conception without creative work all fall within the protection scope of the present invention.

Claims

1. A high-speed wind tunnel kilowatt-level microwave damage test device, characterized in that: A flat plate model (10) is installed in a wind tunnel test section (6) of a high-speed wind tunnel along the wind tunnel incoming flow and along the airflow; a microwave source (1) is installed outside an observation window (5) on one side of the wind tunnel test section (6) of the high-speed wind tunnel, and a high-speed camera (3) and an infrared thermal imager (4) are also installed; incident microwaves emitted by the microwave source (1) are fed into the wind tunnel test section (6) through a circulator (2) and a coupler (8) in sequence and then irradiated onto the surface of the flat plate model (10); a wave-transmitting glass (11) is embedded at the center of the surface of the flat plate model (10) corresponding to the position of the incident microwave, and a wave-absorbing material (12) is arranged away from the wave-transmitting glass ( 11) is coated on the surface of the flat plate model (10), the surface of the wave-transmitting glass (11) and the surface of the wave-absorbing material (12) are located on the same plane; a horn-shaped open waveguide (15) is installed on the back of the wave-transmitting glass (11), the wave-transmitting glass (11) and the open waveguide (15) are sealed by a rubber ring, and the open waveguide (15) is closed on the directional coupler (16); the cable of the directional coupler (16) extends out of the wind tunnel test section (6) and is sequentially connected to an attenuator (17), a detector (18), an oscilloscope (19) and a computer located on the other side of the wind tunnel test section (6); A high-temperature armored thermocouple (14) is embedded in the edge of the flat plate model (10), and the distance between the high-temperature armored thermocouple (14) and the surface of the flat plate model (10) is 1 mm to 2 mm; Along the wind tunnel flow, below the wind tunnel throat (7) of the high-speed wind tunnel, a front reflection microwave absorption plate array (9) is installed above the flat plate model (10), and a rear reflection microwave absorption plate array (13) is installed below the flat plate model (10).

2. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The incident area of ​​the incident microwave is greater than or equal to the surface area of ​​the flat plate model (10).

3. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The material of the flat plate model (10) is aluminum or steel.

4. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The shape of the wave-transmitting glass (11) is circular or square.

5. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The material of the wave-transmitting glass (11) is quartz glass.

6. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The material of the reflective microwave absorption plates in the front reflective microwave absorption plate array (9) and the rear reflective microwave absorption plate array (13) is silicon carbide.

7. The high-speed wind tunnel kilowatt-level microwave damage test device according to claim 1 is characterized in that: The opening diameter of the open waveguide (15) is larger than the wavelength of the incident microwave.

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