A method for positioning and distinguishing a high-temperature gas-solid interface chemical reaction zone

Abstract

The application provides a high-temperature gas-solid interface chemical reaction zone positioning and distinguishing method, which comprises the following steps: first, using a radiation spectrum acquisition system to measure the radiation spectrum of a gas-solid interface of a heatproof material, and obtaining the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heatproof material; then, according to the measured radiation spectrum information, analyzing the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heatproof material, so as to determine the tracer component for chemical reaction zone positioning; then, selecting the tracer component filter of the corresponding wavelength according to the analysis result of the radiation spectrum information, and shooting the radiation image of the chemical reaction zone of the heatproof material by using a high-speed camera provided with the tracer component filter; finally, realizing the positioning and real-time distinguishing of the interface chemical reaction zone between the high-enthalpy flow and the material surface according to the shot radiation image. The application can realize the positioning and real-time distinguishing of the interface chemical reaction zone between the high-enthalpy flow and the material surface, and solves the problem that the positioning of the interface chemical reaction zone between the high-enthalpy flow and the material surface is not clear at present.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hypersonic vehicle aerodynamic heat protection technology, and particularly relates to a method for positioning and distinguishing a high-temperature gas-solid interface chemical reaction zone. BACKGROUND

[0002] When a vehicle is in hypersonic flight, it will face a serious aerodynamic heating problem. The temperature of the gas around the vehicle rises sharply, and then is excited, dissociated and ionized by vibration, and a series of complex chemical reactions occur with the wall heat protection material, including catalysis, oxidation and ablation. The gas-solid interface coupling effect of such high-enthalpy flow gas and heat protection material brings difficulties to the aerodynamic heat protection of the vehicle. Therefore, studying the gas-solid interface chemical reaction zone, accurately analyzing the mechanism of gas-solid coupling effect, and deeply understanding the dynamic evolution law of the complex reactions therebetween can provide data reference for performance evaluation of heat protection materials and provide a basis for the development of vehicle heat protection technology.

[0003] The gas-solid coupling effect occurs at the interface between the high-enthalpy flow and the heat shield material. There is no clear boundary feature in the traditional sense, and numerous high-temperature reactions occur in this region. Therefore, this region is called the high-temperature interface, which is the connection and transition of the traditional gas and solid phase boundaries. Therefore, the related research is usually aimed at the near-wall region of the heat shield material in experimental measurement. In the research of S. Y. Chen et al. (see the paper: Modeling of emission spectra in nonequilibrium plasmas for testing pyrolyzing ablators), the surface position electron temperature of the model was calculated by radiation spectrum to analyze the gas phase interaction mechanism in the boundary layer. Specifically, the radiation spectrum in the range of 0 mm to 4 mm from the model surface was collected by a spectrometer. The results show that even if the measurement position only differs by 1 mm, the electron temperature will show a large difference, indicating that the gas-solid coupling effect in the high-temperature interface has obvious spatial distribution characteristics. In similar gas-solid interface spectrum measurement work, B. Helber et al. chose three different positions every 2 mm on the surface of the heat shield material to collect radiation spectrum (see the paper: Experimental investigation of ablation and pyrolysis processes of carbon-phenolic ablators in atmospheric entry plasmas). Although these studies measure the radiation spectrum at different positions on the surface of the heat shield material to some extent, they reflect the spatial distribution characteristics of the gas-solid coupling effect. However, the limitation of the radiation spectrum measurement method is that it can only obtain local data at a certain point, and cannot fully depict the overall spatial distribution of the high-temperature interface. The specific positioning of the high-temperature interface is still lacking in clarity. This also leads to the current research generally taking the displacement from the material surface as the reference standard for the measurement position, and failing to consider the high-temperature interface itself. The measurement point may not accurately fall within the chemical reaction zone of the gas-solid interface. Especially in the case of material ablation, recession or expansion, and other changes in appearance, this problem is particularly prominent. Therefore, it is crucial to accurately determine the chemical reaction zone of the high-temperature gas-solid interface from the perspective of spatial positioning.

[0004] In addition, there are also studies on the gas-solid interface characteristics by numerical simulation method. Z. Ye et al. (see the paper: A hybrid CFD-RMD multiscale coupling framework for interfacial heat and mass simulation under hyperthermal ablative conditions) combines the micro characteristics of the RMD model with the macro CFD model, and proposes a CFD-RMD multiscale simulation framework. Compared with the radiation spectrum measurement, the numerical simulation can directly show the flow field structure around the heat-resistant material and analyze the overall gas-solid interface. However, the simulation method lacks experimental data verification, and the actual high-temperature gas-solid interface chemical reaction zone needs to be further analyzed.

[0005] In summary, the current related research lacks clear positioning of the high-temperature gas-solid interface chemical reaction zone of the heat-resistant material, so that there is a lack of clear reference standard for experimental measurement of gas-solid coupling effect, and the numerical simulation results also lack experimental data verification. Therefore, it is necessary to further innovate the existing technology to realize accurate positioning and in-depth research of the high-temperature gas-solid interface chemical reaction zone, and provide a more solid foundation for the development of aircraft thermal protection technology. SUMMARY

[0006] In view of the technical problems in the above background art, the present application provides a high-temperature gas-solid interface chemical reaction zone positioning and analysis method, which can realize the positioning and real-time analysis of the interface chemical reaction zone between high-enthalpy flow and material surface, solve the problem that the current research is not clear about the positioning of the interface chemical reaction zone between high-enthalpy flow and material surface, provide subsequent guidance for accurate measurement and numerical simulation of the gas-solid interface, and provide further solution ideas for the development of aircraft thermal protection technology.

[0007] To solve the above technical problems, the present application provides a high-temperature gas-solid interface chemical reaction zone positioning and analysis method, which comprises the following steps:

[0008] (1) First, use a radiation spectrum acquisition system to measure the radiation spectrum of the gas-solid interface of the heat-resistant material, and obtain the radiation spectrum information of the gas-solid interface chemical reaction zone of the heat-resistant material;

[0009] (2) Then, according to the measured radiation spectrum information, analyze the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat-resistant material to determine the tracer component for chemical reaction zone positioning;

[0010] (3) according to the radiation spectrum information analysis results selection corresponding wavelength tracer component filter, the tracer component filter is installed on the high-speed camera, then through the tracer component filter installed on the high-speed camera to shoot the radiation image of the chemical reaction zone of the heat-resistant material, finally according to the radiation image realizes high enthalpy flow and material surface interface chemical reaction zone positioning and real-time analysis.

[0011] The high-temperature gas-solid interface chemical reaction zone positioning and analysis method, wherein the radiation spectrum acquisition system in the step (1) comprises a plasma device and a spectrometer matched with the plasma device on one side of the plasma device.

[0012] The heat-resistant material is installed in the test cabin of the plasma device and aligned with the center of the nozzle for ejecting plasma, used for simulating the thermal environment of the hypersonic aircraft.

[0013] In the step (1), the plasma generated by the plasma device acts on the surface of the heat-resistant material to provide a high-enthalpy flow environment for the material.

[0014] In the step (1), the radiation spectrum of the gas-solid interface of the heat-resistant material is collected by the spectrometer, and the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heat-resistant material is obtained, so as to provide data for subsequent analysis of the main chemical components of the surface chemical reaction zone of the heat-resistant material.

[0015] The high-temperature gas-solid interface chemical reaction zone positioning and analysis method, wherein the plasma device adopts an inductively coupled plasma device or an arc-heated plasma device.

[0016] The high-temperature gas-solid interface chemical reaction zone positioning and analysis method, wherein the specific steps for analyzing the chemical components of the chemical reaction zone on the surface of the heat-resistant material and the corresponding wavelength in the step (2) are:

[0017] (2.1) read the obtained radiation spectrum information, draw the spectrum line image, the horizontal axis is the wavelength, and the vertical axis is the relative radiation intensity;

[0018] (2.2) select the spectrum line with intensity obviously higher than 0 and not too exposed, according to the wavelength of these spectrum lines and the chemical element composition of the environment, query the publicly used spectrum database, find the corresponding elements of these radiation spectrum lines, then select the components from these elements that can reflect the interaction between the heat-resistant material and the plasma, so as to determine the tracer component and the corresponding wavelength of the high-temperature gas-solid interface chemical reaction zone of the heat-resistant material, and provide reference for subsequent positioning and analysis of the chemical reaction zone.

[0019] The high-temperature gas-solid interface chemical reaction zone positioning and distinguishing method, wherein: in the step (3), the radiation image of the filter wavelength is shot by the high-speed camera, which is the radiation image of the chemical reaction zone of the heat-proof material.

[0020] The high-temperature gas-solid interface chemical reaction zone positioning and distinguishing method, wherein: in the step (3), the radiation image of the filter wavelength is shot by the high-speed camera at a maximum resolution of 1600*1600 and a frame rate of 600 fps, so as to realize the positioning and real-time distinguishing of the gas-solid interface chemical reaction zone.

[0021] The high-temperature gas-solid interface chemical reaction zone positioning and distinguishing method, wherein: in the step (3), the positioning and real-time distinguishing of the high-enthalpy flow and the interface chemical reaction zone of the material surface are realized by using the shot tracer component radiation image, and the area with obvious brightness in the radiation image represents the high gas-solid interface chemical reaction zone, and the brightness of the radiation image represents the radiation intensity in the chemical reaction zone, so as to analyze and determine the spatial range of the high-temperature gas-solid interface chemical reaction zone and the radiation spatial distribution of the chemical reaction zone.

[0022] By using the above technical solution, the present application has the following beneficial effects:

[0023] The high-temperature gas-solid interface chemical reaction zone positioning and distinguishing method has reasonable conception and simple process, the high-speed camera with the filter can accurately depict the overall spatial distribution characteristics of the high-temperature interface and realize the accurate positioning of the high-temperature interface, which not only provides a clear reference for the experimental measurement of the gas-solid coupling effect, but also provides experimental data verification for the numerical simulation, and helps to deeply understand the gas-solid coupling effect of the high-temperature interface of the heat-proof material.

[0024] The present application provides an effective scheme for the real-time positioning of the gas-solid interface chemical reaction zone of the heat-proof material under the aerodynamic heating test, can realize the positioning and real-time distinguishing of the interface chemical reaction zone of the high-enthalpy flow and the material surface, can solve the problem that the positioning of the interface chemical reaction zone of the high-enthalpy flow and the material surface is not clear, can provide subsequent guidance for the accurate measurement and numerical simulation of the gas-solid interface, and provide further solution ideas for the development of the thermal protection technology of the aircraft. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0026] Figure 1A schematic diagram of the collection principle of the radiation spectrum and the radiation image in the embodiment of the present application;

[0027] Figure 2 The surface spectrum images of four kinds of heat-proof materials, C / SiC, SiC, C / SiC-ZrB2 and SiO2, measured by the radiation spectrum collection system in the embodiment of the present application;

[0028] Figure 3 A frame of the C / SiC heat-proof material in the visible light video and the CN radiation image of the chemical reaction zone of the gas-solid interface of the C / SiC heat-proof material taken by the high-speed camera in the embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be described clearly and completely in combination with the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0030] The present application will be further explained and described in combination with the specific embodiments.

[0031] As shown in the figure, the method for positioning and analyzing the high-temperature gas-solid interface chemical reaction zone provided by the present embodiment comprises the following steps: Figure 1

[0032] (1) First, measure the radiation spectrum of the heat-proof material gas-solid interface (the interface where the heat-proof material surface contacts with the plasma) by using the radiation spectrum collection system, to obtain the radiation spectrum information at the material surface;

[0033] (2) Then, analyze the chemical components and corresponding wavelengths of the chemical reaction zone of the heat-proof material surface chemical reaction zone according to the measured radiation spectrum information, to determine the tracer component used for the chemical reaction zone positioning;

[0034] (3) Then, select the tracer component filter of the corresponding wavelength according to the analysis result of the radiation spectrum information, and install the tracer component filter on the high-speed camera. The radiation image of the chemical reaction zone of the heat-proof material can be taken by the high-speed camera with the tracer component filter installed, so as to realize the positioning and real-time analysis of the interface chemical reaction zone of the high-enthalpy flow and the material surface.

[0035] In the embodiment of the present application, the radiation spectrum collection system shown in the solid frame is used to measure the radiation spectrum at the surface position of the heat-proof material, to analyze the main chemical components of the heat-proof material surface chemical reaction zone; Figure 1

[0036] The above-mentioned radiation spectrum collection system comprises a plasma device and a spectrometer. ​​

[0037] The heatproof material used in the embodiment of the present application is C / SiC, SiC, C / SiC-ZrB2 and SiO2 heatproof material, which are respectively installed in a plasma device to simulate the thermal environment of a hypersonic aircraft in flight;

[0038] The plasma device described above is composed of an ICP generator, a supersonic nozzle, a test cabin and a vacuum system; wherein the heatproof material chamber is installed in the test cabin of the plasma device and is aligned with the center of the plasma ejection nozzle, for simulating the thermal environment of a hypersonic aircraft in flight; the gas enters the ICP generator to generate plasma which is ejected by the supersonic nozzle and acts on the surface of the heatproof material, and the plasma flows through the heatproof material and is collected by the vacuum system.

[0039] Further, the radiation spectrum of the gas-solid interface of the four kinds of heatproof materials is collected respectively by using a spectrometer, and the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heatproof material is obtained, so as to provide data for subsequent analysis of the main chemical components of the surface chemical reaction zone of the heatproof material.

[0040] Further, according to the measured radiation spectrum information of the C / SiC, SiC, C / SiC-ZrB2 and SiO2 heatproof materials, the specific steps for analyzing the chemical components of the surface chemical reaction zone of each heatproof material and the corresponding wavelength in the embodiment of the present application are as follows:

[0041] ① Read the radiation spectrum information collected each time, and draw the spectral line images of the surfaces of the C / SiC, SiC, C / SiC-ZrB2 and SiO2 heatproof materials as shown in FIG. 1, wherein the horizontal axis is the wavelength and the vertical axis is the relative radiation intensity; Figure 2

[0042] ② For the C / SiC heatproof material, one or more spectral lines with intensity obviously higher than 0 and not too exposed are found near the wavelength of 388 nm, according to the spectral line wavelength and the chemical element composition of the environment, the publicly used spectrum database (specifically, NIST database) is queried to determine that the spectral line is a CN radiation spectral line. This element reflects that the C in the C / SiC heatproof material has interacted with the plasma, so that the main chemical component of the high-temperature gas-solid interface chemical reaction zone of the C / SiC heatproof material is analyzed as CN, and the corresponding wavelength is 388 nm, which is used as a tracer component to provide a reference for subsequent positioning and analysis of the chemical reaction zone. Similarly, the tracer component of the SiC heatproof material is N2 + , the corresponding wavelength is 391 nm; the tracer component of the C / SiC-ZrB2 heatproof material is Si, the corresponding wavelength is 390.55 nm; and the tracer component of the SiO2 heatproof material is Si, the corresponding wavelength is 390.55 nm.

[0043] In the embodiment of the present application, for clearer and more concise description, the following Figure 1 ​The high-speed camera with filter shown in the dashed box photographs the radiation image of the chemical reaction zone of the C / SiC heat-resistant material in the four materials, thereby positioning and analyzing the chemical reaction zone of the gas-solid interface in real time.

[0044] The filter described above is installed in front of the high-speed camera and can photograph the radiation image of a certain wavelength; wherein, the wavelength filtered by the filter is also selectively selected according to different materials, such as the C / SiC, SiC, C / SiC-ZrB2 and SiO2 heat-resistant materials in the embodiment, and according to the analysis above, the filters of 388 nm, 391 nm, 390.55 nm and 390.55 nm should be selected respectively.

[0045] The high-speed camera described above can photograph high frame rate and high resolution at a frame rate of 600 fps under a resolution of 1600*1600, thereby realizing the positioning and real-time analysis of the chemical reaction zone of the gas-solid interface.

[0046] Further, the specific method for positioning and analyzing the chemical reaction zone of the gas-solid interface of the C / SiC heat-resistant material is as follows:

[0047] According to the spectral analysis result, the CN filter of 388 nm wavelength is selected and installed on the high-speed camera; the CN radiation image in the wavelength range is photographed by the high-speed camera, which is the radiation image of the chemical reaction zone of the C / SiC heat-resistant material, thereby realizing the positioning and real-time analysis of the chemical reaction zone of the high-enthalpy flow and the material surface.

[0048] Further, the positioning and real-time analysis of the chemical reaction zone of the high-enthalpy flow and the material surface is realized by using the photographed radiation image of the tracer component; the area with obvious brightness in the radiation image represents the high gas-solid interface chemical reaction zone, and the brightness of the radiation image represents the radiation intensity in the chemical reaction zone, thereby analyzing and determining the spatial range of the high-temperature gas-solid interface chemical reaction zone and the radiation spatial distribution of the chemical reaction zone. The photographing result of the high-speed camera is shown in Figure 3 The left side is a frame of visible light video of the C / SiC heat-resistant material in the plasma flow, to show the overall structure of the heat-resistant material and the flow field, and the right side is the CN radiation image of the C / SiC heat-resistant material photographed by the high-speed camera, wherein the part in the red dashed line is the gas-solid interface chemical reaction zone positioned in the embodiment; in order to show the radiation intensity, the image is processed by pseudo-color, wherein different colors in the CN radiation image represent the relative intensity of the radiation, the red color is the strongest, and the blue color is the weakest. It can be seen that the radiation intensity distribution of the whole chemical reaction zone is not uniform, which not only reflects the spatial range of the high-temperature gas-solid interface chemical reaction zone, but also reflects the radiation spatial distribution of the chemical reaction zone, thereby realizing the positioning and analysis of the high-temperature gas-solid interface chemical reaction zone of the C / SiC heat-resistant material.

[0049] Further, the plasma is generated by using an inductively coupled plasma device or an arc-heated plasma equipment and acts on the surface of the heat-resistant material to provide a high-enthalpy flow environment for the material.

[0050] The present application can realize positioning and real-time analysis of the interface chemical reaction zone of high-enthalpy flow and the material surface, solve the problem that the positioning of the interface chemical reaction zone of high-enthalpy flow and the material surface is not clear at present, provide subsequent guidance for accurate measurement and numerical simulation of the gas-solid interface, and provide further solution ideas for the development of aircraft thermal protection technology.

[0051] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for locating and identifying the chemical reaction zone at a high-temperature gas-solid interface, characterized in that, Includes the following steps: (1) First, use a radiation spectral acquisition system to measure the radiation spectrum of the gas-solid interface of the heat-resistant material to obtain the radiation spectral information of the chemical reaction zone of the gas-solid interface of the heat-resistant material. (2) Then, based on the measured radiation spectrum information, analyze the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat-resistant material to determine the tracer component used for locating the chemical reaction zone; (3) Then, based on the results of the radiation spectrum information analysis, select the corresponding wavelength tracer component filter, install the tracer component filter on the high-speed camera, and then use the high-speed camera with the tracer component filter installed to take a radiation image of the chemical reaction zone of the heat-resistant material. Finally, based on the taken radiation image, the location and real-time identification of the interface chemical reaction zone between the high enthalpy flow and the material surface are realized. In step (3), the location and real-time identification of the chemical reaction zone at the interface between the high enthalpy flow and the material surface are specifically achieved by taking a tracer component radiation image. The area with obvious brightness in the radiation image represents the chemical reaction zone at the high gas-solid interface, and the brightness of the radiation image represents the radiation intensity within the chemical reaction zone. Based on this, the spatial range of the chemical reaction zone at the high temperature gas-solid interface and the radiation spatial distribution of the chemical reaction zone are analyzed and determined.

2. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone as described in claim 1, characterized in that: The radiation spectral acquisition system in step (1) includes a plasma device and a spectrometer matched and installed on one side of the plasma device; The heat-resistant material is installed in the test chamber of the plasma device and aligned with the center of the plasma ejection nozzle to simulate the thermal environment of a hypersonic aircraft. In step (1), plasma is generated using the plasma device and applied to the surface of the heat-resistant material to provide a high-enthalpy flow environment for the material. In step (1), the radiation spectrum of the gas-solid interface of the heat-resistant material is collected by the spectrometer and the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heat-resistant material is obtained, so as to provide data for subsequent analysis of the main chemical components of the chemical reaction zone on the surface of the heat-resistant material.

3. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone as described in claim 2, characterized in that: The plasma equipment is either an inductively coupled plasma device or an arc-heated plasma device.

4. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone as described in claim 1, characterized in that, The specific steps for analyzing the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat-resistant material in step (2) are as follows: (2.1) Read the obtained radiation spectrum information and draw the spectral image, with the horizontal axis representing wavelength and the vertical axis representing relative radiation intensity; (2.2) Select spectral lines with an intensity significantly higher than 0 without overexposure. Based on the wavelength of these spectral lines and the chemical element composition of the environment, search publicly available spectral databases to find the corresponding elements of these radiation spectral lines. Then, select the components that can reflect the interaction between the heat protection material and the plasma from these elements, thereby determining the tracer components and corresponding wavelengths of the high-temperature gas-solid interface chemical reaction zone of the heat protection material, providing a reference for the subsequent location and identification of the chemical reaction zone.

5. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone as described in claim 1, characterized in that: In step (3), the radiation image of the filtered length of the filter is captured by a high-speed camera, which is the radiation image of the chemical reaction zone of the heat-resistant material.

6. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone as described in claim 1, characterized in that: In step (3), the high-speed camera captures radiation images filtered by the filter at a resolution of up to 1600*1600 and a frame rate of 600fps, thereby enabling the location and real-time identification of the chemical reaction zone at the gas-solid interface.

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