High-temperature gas-solid interface chemical reaction zone positioning and discriminating method

Abstract

The invention provides a high-temperature gas-solid interface chemical reaction region positioning and discriminating method, which comprises the following steps of: measuring a gas-solid interface radiation spectrum of a heat-proof material by using a radiation spectrum acquisition system to obtain radiation spectrum information of a gas-solid interface chemical reaction region of the heat-proof material; according to the measured radiation spectrum information, chemical components and corresponding wavelengths of a chemical reaction area on the surface of the heat-proof material are analyzed so as to determine tracer components for positioning the chemical reaction area; selecting a tracing component optical filter with a corresponding wavelength according to a radiation spectrum information analysis result, shooting a radiation image of a chemical reaction area of the heat-proof material through a high-speed camera provided with the tracing component optical filter, and finally realizing positioning and real-time analysis of the interface chemical reaction area of high-enthalpy flow and the surface of the material according to the shot radiation image. According to the invention, the positioning and real-time analysis of the interface chemical reaction zone of the high enthalpy flow and the material surface can be realized, and the problem that the positioning of the interface chemical reaction zone of the high enthalpy flow and the material surface is not clear in the current research is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of aerodynamic thermal protection for hypersonic vehicles, and in particular to a method for locating and distinguishing a chemical reaction zone at a high-temperature gas-solid interface. Background Art

[0002] Aircraft will face severe aerodynamic heating problems when flying at hypersonic speeds. The temperature of the gas around the aircraft rises significantly, and then it is excited by vibration, dissociated and ionized, and undergoes a series of complex chemical reactions with the wall thermal protection material, including catalysis, oxidation and ablation. The gas-solid interface coupling between this high-enthalpy flowing gas and the thermal protection material brings difficulties to the aerodynamic thermal protection of the aircraft. Therefore, studying the chemical reaction zone of the gas-solid interface, accurately analyzing the gas-solid coupling mechanism, and deeply understanding the dynamic evolution of the complex reactions in between can provide data reference for the performance evaluation of thermal protection materials and provide a basic basis for the development of aircraft thermal protection technology.

[0003] The gas-solid coupling effect occurs at the interface where the high-enthalpy incoming flow contacts the heat-resistant material. There is no clear boundary feature in the traditional sense. Many high-temperature reactions occur here, so this area is called the high-temperature interface. It is the connection and transition between the traditional gas phase and the solid phase boundary. Therefore, related studies usually target the near-wall area of ​​the heat-resistant material during experimental measurements. In the study of SY Chen et al. (see paper: Modeling of emission spectra in nonequilibrium plasmas for testing pyrolyzing ablators), the electron temperature at the surface position of the model was calculated by radiation spectrum to analyze the gas-phase interaction mechanism in the boundary layer. Specifically, the radiation spectrum within the range of 0 mm to 4 mm from the model surface was collected using a spectrometer. The results show that even if the measurement position is only 1 mm different, the electron temperature will show a large difference. It can be seen that the gas-solid coupling effect in the high-temperature interface has obvious spatial distribution characteristics. In similar work on the spectral measurement of gas-solid interface, B. Helber et al. chose to collect radiation spectra at three different positions on the surface of the heat-resistant material at intervals of 2 mm (see paper: Experimental investigation of ablation and pyrolysis processes of carbon-phenolic ablators in atmospheric entry plasmas). Although these studies have reflected the spatial distribution characteristics of the gas-solid coupling effect to a certain extent by measuring the radiation spectra at different positions on the surface of the heat-resistant material, the limitation of the radiation spectrum measurement method is that it can only obtain local data at a certain point, and cannot fully describe the overall spatial distribution of the high-temperature interface, and the specific positioning of the high-temperature interface is still unclear. This also leads to the current research generally using the displacement from the material surface as the reference standard for the measurement position, failing to consider the high-temperature interface itself, and the measurement point may not accurately fall within the chemical reaction zone of the gas-solid interface. This problem is particularly prominent when the material undergoes morphological changes such as ablation retreat or expansion. 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] There are also studies that use numerical simulation methods to explore the characteristics of the gas-solid interface. Z.Ye et al. (see paper: Ahybrid CFD-RMD multiscale coupling framework for interfacial heat and mass simulation under hyperthermal ablative conditions) combined the microscopic characteristics of the RMD model with the macroscopic CFD model and proposed a CFD-RMD multiscale simulation framework. Compared with radiation spectrum measurement, numerical simulation can intuitively display 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 identified.

[0005] In summary, the current related research lacks a clear positioning of the high-temperature gas-solid interface chemical reaction zone of thermal protection materials, resulting in a lack of clear reference standards for experimental measurements of gas-solid coupling effects, and the numerical simulation results also lack experimental data verification. Therefore, it is necessary to further innovate existing technologies to achieve accurate positioning and in-depth research on the high-temperature gas-solid interface chemical reaction zone, providing a more solid foundation for the development of aircraft thermal protection technology. Summary of the invention

[0006] In response to the technical problems existing in the above-mentioned background technology, the present invention proposes a method for locating and identifying the chemical reaction zone at the high-temperature gas-solid interface, which can realize the positioning and real-time identification of the chemical reaction zone at the interface between high enthalpy flow and the material surface, and solves the problem of unclear positioning of the chemical reaction zone at the interface between high enthalpy flow and the material surface in current research, provides follow-up guidance for the precise measurement and numerical simulation of the gas-solid interface, and provides further solutions for the development of aircraft thermal protection technology.

[0007] In order to solve the above technical problems, the present invention provides a method for locating and distinguishing a high-temperature gas-solid interface chemical reaction zone, 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 to obtain the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heat-resistant material;

[0009] (2) Then, based on the measured radiation spectrum information, the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat protection material are analyzed to determine the tracer component used for locating the chemical reaction zone;

[0010] (3) According to the analysis results of the radiation spectrum information, a tracer component filter of the corresponding wavelength is selected, and the tracer component filter is installed on a high-speed camera. Then, the radiation image of the chemical reaction zone of the heat-resistant material is captured by the high-speed camera equipped with the tracer component filter. Finally, the interface chemical reaction zone between the high enthalpy flow and the material surface is located and identified in real time based on the captured radiation image.

[0011] The method for locating and distinguishing the chemical reaction zone at the high-temperature gas-solid interface, wherein: the radiation spectrum acquisition system in step (1) comprises a plasma device and a spectrometer matched and arranged on one side of the plasma device;

[0012] The heat protection material is installed in the test chamber of the plasma equipment and is aligned with the center of the nozzle that ejects plasma, so as to simulate the thermal environment of the aircraft flying at a hypersonic speed;

[0013] In the step (1), the plasma device is used to generate plasma, which 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 spectrometer is used to collect the radiation spectrum of the gas-solid interface of the heat-resistant material and obtain the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heat-resistant material, so as to provide data for the subsequent analysis of the main chemical components of the chemical reaction zone on the surface of the heat-resistant material;

[0015] The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone, wherein: the plasma equipment adopts an inductively coupled plasma device or an arc heating plasma equipment.

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

[0017] (2.1) Read the obtained radiation spectrum information and draw a spectrum line image with the horizontal axis being the wavelength and the vertical axis being the relative radiation intensity;

[0018] (2.2) Select spectral lines whose intensity is significantly higher than 0 but not overexposed. According to the wavelength of these spectral lines and the chemical element composition of the environment, query the publicly available spectral database to find the elements corresponding to these radiation spectral lines. Then, select the components that can reflect the interaction between the heat shield material and the plasma from these elements, so as to determine the tracer components and corresponding wavelengths of the high-temperature gas-solid interface chemical reaction zone of the heat shield material, and provide a reference for the subsequent positioning and identification of the chemical reaction zone.

[0019] The method for locating and identifying the chemical reaction zone at the high-temperature gas-solid interface, wherein: in the step (3), a radiation image filtered by the filter is photographed by a high-speed camera, that is, a radiation image of the chemical reaction zone of the heat-resistant material.

[0020] The method for locating and identifying the chemical reaction zone at a high temperature gas-solid interface, wherein: the high-speed camera in step (3) captures the radiation image filtered by the filter at a maximum resolution of 1600*1600 and a frame rate of 600fps, thereby realizing the positioning and real-time identification of the chemical reaction zone at the gas-solid interface.

[0021] The method for locating and identifying the chemical reaction zone at the high-temperature gas-solid interface, wherein: the locating and real-time identification of the chemical reaction zone at the interface between the high-enthalpy flow and the material surface in the step (3) is specifically achieved by using the radiation image of the tracer component taken, and the area with obvious brightness in the radiation image represents the high-temperature 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 chemical reaction zone at the high-temperature gas-solid interface and the radiation spatial distribution of the chemical reaction zone.

[0022] By adopting the above technical solution, the present invention has the following beneficial effects:

[0023] The method for locating and identifying the chemical reaction zone of the high-temperature gas-solid interface of the present invention is rationally conceived and has a simple process. The overall spatial distribution characteristics of the high-temperature interface can be accurately depicted by a high-speed camera equipped with a filter, and the high-temperature interface can be accurately positioned. This not only provides a clear and definite reference benchmark for the experimental measurement of the gas-solid coupling effect, but also provides experimental data verification for numerical simulation work, which is helpful to deeply understand the gas-solid coupling effect of the high-temperature interface of heat-resistant materials.

[0024] The present invention proposes an effective solution for the real-time positioning of the chemical reaction zone at the gas-solid interface of the heat-resistant material under the aerodynamic thermal test, which can realize the positioning and real-time analysis of the interface chemical reaction zone between the high enthalpy flow and the material surface, and can solve the problem of unclear positioning of the interface chemical reaction zone between the high enthalpy flow and the material surface in current research. It can provide follow-up guidance for the precise measurement and numerical simulation of the gas-solid interface, and provide further solutions for the development of aircraft thermal protection technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0027] Figure 2 The surface spectrum images of four heat-resistant materials, namely C / SiC, SiC, C / SiC-ZrB2 and SiO2, are respectively measured using a radiation spectrum acquisition system in an embodiment of the present invention;

[0028] Figure 3 It is a frame of the C / SiC heat shield material in the visible light video and the CN radiation image of the gas-solid interface chemical reaction zone of the C / SiC heat shield material taken by a high-speed camera in an example of the present invention. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention is further explained below in conjunction with specific implementation modes.

[0031] like Figure 1 As shown, the present embodiment provides a method for locating and distinguishing a high-temperature gas-solid interface chemical reaction zone, comprising the following steps:

[0032] (1) First, use a radiation spectrum acquisition system to measure the radiation spectrum of the gas-solid interface of the heat-resistant material (the interface where the surface of the heat-resistant material contacts the plasma) to obtain radiation spectrum information on the surface of the material;

[0033] (2) then analyzing the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat protection material based on the measured radiation spectrum information to determine the tracer component used for locating the chemical reaction zone;

[0034] (3) According to the analysis results of the radiation spectrum information, a tracer component filter of the corresponding wavelength is selected, and the tracer component filter is installed on a high-speed camera. The radiation image of the chemical reaction zone of the heat-resistant material can be captured by the high-speed camera equipped with the tracer component filter, thereby realizing the positioning and real-time identification of the interface chemical reaction zone between the high enthalpy flow and the material surface.

[0035] In the embodiment of the present invention, by Figure 1 The radiation spectrum acquisition system shown in the solid line frame measures the radiation spectrum at the surface of the heat protection material to identify the main chemical components of the chemical reaction area on the surface of the heat protection material;

[0036] The above-mentioned radiation spectrum acquisition system includes a plasma device and a spectrometer.

[0037] The heat-resistant materials used in the embodiments of the present invention are C / SiC, SiC, C / SiC-ZrB2, and SiO2 heat-resistant materials, which are respectively installed in plasma equipment to simulate the thermal environment of an aircraft flying at hypersonic speed;

[0038] The above-mentioned plasma equipment consists of an ICP generator, a supersonic nozzle, a test chamber and a vacuum system; wherein, the heat protection material chamber is installed in the test chamber of the plasma equipment and is aligned with the center of the nozzle that ejects plasma, so as to simulate the thermal environment of an aircraft flying at a hypersonic speed; after the gas enters the ICP generator, plasma is generated and ejected from the supersonic nozzle, acting on the surface of the heat protection material; after the plasma flows through the heat protection material, it is collected by the vacuum system.

[0039] Furthermore, a spectrometer is used to collect the radiation spectra of the gas-solid interfaces of the four heat-resistant materials and obtain the radiation spectrum information of the chemical reaction zone of the gas-solid interface of the heat-resistant materials, so as to provide data for the subsequent analysis of the main chemical components of the chemical reaction zone on the surface of the heat-resistant materials.

[0040] Furthermore, in the embodiment of the present invention, according to the measured radiation spectrum information of C / SiC, SiC, C / SiC-ZrB2, and SiO2 heat-resistant materials, the specific steps of analyzing the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of each heat-resistant material are as follows:

[0041] ① Read the radiation spectrum information collected each time and draw the following Figure 2 The spectral line images of the surfaces of C / SiC, SiC, C / SiC-ZrB2, and SiO2 heat protection materials shown, with the horizontal axis being the wavelength and the vertical axis being the relative radiation intensity;

[0042] ② For C / SiC heat shielding materials, find one or more spectral lines with intensities significantly higher than 0 and not overexposed near the wavelength of 388nm. According to the wavelength of the spectral line and the chemical element composition of the environment, query the publicly available spectral database (specifically the NIST database) and determine that the spectral line is a CN radiation line. This element reflects that the C in the C / SiC heat shielding material interacts with the plasma, thereby analyzing that the main chemical component of the high-temperature gas-solid interface chemical reaction zone of the C / SiC heat shielding material is CN, corresponding to a wavelength of 388nm, and using it as a tracer component to provide a reference for the subsequent positioning and identification of the chemical reaction zone. Similarly, it can be determined that the tracer component of the SiC heat shielding material is N2 + , the corresponding wavelength is 391nm; the tracer component of C / SiC-ZrB2 thermal protection material is Si, the corresponding wavelength is 390.55nm; the tracer component of SiO2 thermal protection material is Si, the corresponding wavelength is 390.55nm.

[0043] In the embodiment of the present invention, for a clearer and more concise description, Figure 1The high-speed camera equipped with a filter shown in the dotted box captured the radiation image of the chemical reaction zone of the C / SiC heat-resistant material among the four materials, so as to locate and distinguish the chemical reaction zone of the gas-solid interface in real time;

[0044] The above-mentioned filter is installed in front of the high-speed camera and can capture radiation images of a certain wavelength; wherein, the wavelength filtered by the filter is also selectively selected according to different materials. For example, for the C / SiC, SiC, C / SiC-ZrB2, and SiO2 heat-resistant materials in this embodiment, from the previous analysis, filters of 388nm, 391nm, 390.55nm, and 390.55nm should be selected respectively.

[0045] The above-mentioned high-speed camera can shoot high frame rate and high resolution at a maximum resolution of 1600*1600 and a frame rate of 600fps, realizing the positioning and real-time identification of the chemical reaction zone at the gas-solid interface.

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

[0047] According to the results of spectral analysis, a CN filter that can pass 388nm wavelength is selected and installed on the high-speed camera; the CN radiation image within this wavelength range is captured 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 identification of the interface chemical reaction zone between the high enthalpy flow and the material surface.

[0048] Furthermore, the location and real-time identification of the interface chemical reaction zone between high enthalpy flow and material surface is realized by using the 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. 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. The results of high-speed camera shooting are shown in the figure below. Figure 3 As shown, the left side is a frame of visible light video of C / SiC heat shield material in plasma flow to show the overall structure of the heat shield material and flow field, and the right side is a CN radiation image of C / SiC heat shield material taken by a high-speed camera, wherein the portion within the red dotted frame is the gas-solid interface chemical reaction zone located in the example of the present invention; to show the intensity of radiation, the image is processed by pseudo-color, wherein different colors in the CN radiation image represent the relative intensity of radiation, red is the strongest, and blue is the weakest. It can be seen that the radiation intensity distribution of the entire 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 spatial distribution of radiation in the chemical reaction zone, thereby realizing the positioning and identification of the high-temperature gas-solid interface chemical reaction zone of the C / SiC heat shield material.

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

[0050] The present invention can realize the positioning and real-time identification of the interfacial chemical reaction zone between high enthalpy flow and material surface, solving the problem of unclear positioning of the interfacial chemical reaction zone between high enthalpy flow and material surface in current research, providing follow-up guidance for the precise measurement and numerical simulation of the gas-solid interface, and providing further solutions 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 invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for locating and distinguishing a high-temperature gas-solid interface chemical reaction zone, characterized in that: The following steps are involved: (1) First, use a radiation spectrum acquisition system to measure the radiation spectrum of the gas-solid interface of the heat-resistant material to obtain the radiation spectrum 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, the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat protection material are analyzed to determine the tracer component used for locating the chemical reaction zone; (3) According to the analysis results of the radiation spectrum information, a tracer component filter of the corresponding wavelength is selected, and the tracer component filter is installed on a high-speed camera. Then, the radiation image of the chemical reaction zone of the heat-resistant material is captured by the high-speed camera equipped with the tracer component filter. Finally, the interface chemical reaction zone between the high enthalpy flow and the material surface is located and identified in real time based on the captured radiation image.

2. The method for locating and identifying a high-temperature gas-solid interface chemical reaction zone according to claim 1, characterized in that: The radiation spectrum acquisition system in step (1) comprises a plasma device and a spectrometer matched and arranged on one side of the plasma device; The heat protection material is installed in the test chamber of the plasma equipment and is aligned with the center of the nozzle that ejects plasma, so as to simulate the thermal environment of the aircraft flying at a hypersonic speed; In the step (1), the plasma device is used to generate plasma, which acts on the surface of the heat-resistant material to provide a high enthalpy flow environment for the material; 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 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 according to claim 2, characterized in that: The plasma equipment adopts an inductively coupled plasma device or an arc heating plasma equipment.

4. The method for locating and identifying the high-temperature gas-solid interface chemical reaction zone according to claim 1, characterized in that: The specific steps of analyzing the chemical composition and corresponding wavelength of the chemical reaction zone on the surface of the heat-resistant material in step (2) are: (2.1) Read the obtained radiation spectrum information and draw a spectrum line image with the horizontal axis being the wavelength and the vertical axis being the relative radiation intensity; (2.2) Select spectral lines whose intensity is significantly higher than 0 but not overexposed. According to the wavelength of these spectral lines and the chemical element composition of the environment, query the publicly available spectral database to find the elements corresponding to these radiation spectral lines. Then, select the components that can reflect the interaction between the heat shield material and the plasma from these elements, so as to determine the tracer components and corresponding wavelengths of the high-temperature gas-solid interface chemical reaction zone of the heat shield material, and provide a reference for the subsequent positioning and identification of the chemical reaction zone.

5. The method for locating and identifying a high-temperature gas-solid interface chemical reaction zone according to claim 1, characterized in that: In the step (3), a high-speed camera is used to capture the radiation image of the filter, that is, the radiation image of the chemical reaction zone of the heat-resistant material.

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

7. The method for locating and identifying a high-temperature gas-solid interface chemical reaction zone according to claim 1, characterized in that: In the step (3), the positioning and real-time identification of the interface chemical reaction zone between the high enthalpy flow and the material surface is specifically achieved by using the captured radiation image of the tracer component, 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, thereby analyzing and determining 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.

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