Method, system, device and storage medium for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum

Abstract

A method, system, device, and storage medium for inverting the vibrational-rotational temperature of a tail flame / shock wave based on a non-equilibrium OH spectrum. The method comprises: deriving a formula for spectral line intensity under a non-equilibrium state; determining a strategy for inverting the vibrational-rotational temperature of the tail flame; determining the temperature step length of the shock wave based on the derived formula for spectral line intensity under a local non-equilibrium thermodynamic state and the change in the shock wave temperature range and the particle number distribution at high temperature; and determining a method for inverting the vibrational-rotational temperature of the shock wave. The system, device, and storage medium invert the vibrational-rotational temperature of a tail flame / shock wave based on the non-equilibrium OH spectrum through functional modules in the system. The present invention focuses on utilizing the structural characteristics of the spectrum, combining the inverted rotational temperature peak in the 0-0 band and the inverted vibration temperature peak in the 1-1 band, thereby improving the utilization rate of the spectrum and taking into account the physical significance of the vibrational-rotational coupling transition during the temperature inversion process, thereby ensuring calculation accuracy and greatly improving the inversion efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of aircraft detection technology, and in particular relates to a method, system, device and storage medium for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum. Background Art

[0002] With the continuous development of aerospace, the demand for accurate and rapid detection of high-speed vehicles is also increasing. During the flight of a high-speed vehicle, a bow shock layer forms in the warhead. In addition, the propellant burns in the nozzle and undergoes a chemical reaction to produce a tail plume. The vibrational-rotational transitions of molecular atoms within the shock layer and tail plume cause the flow field to be in a state of local thermodynamic non-equilibrium. Measuring the vibrational and rotational temperatures of characteristic molecules in the shock layer and tail plume flow field of a high-speed vehicle is of great significance for research on characteristic temperature inversion of shock waves and tail plumes, as well as early warning detection of hypersonic targets.

[0003] Existing temperature measurement technologies based on molecular radiation spectroscopy include the Boltzmann plot slope temperature measurement method: using the intensity calculation formula of the radiation spectrum, the Boltzmann curve is drawn through the P, Q, and R branches of the high-resolution spectrum, and the rotational temperature and vibrational temperature are derived from the slope of the curve. This method requires high resolution. The second method is to compare the spectrum with the experimental spectrum through software fitting, and continuously change the vibrational temperature and rotational temperature to change the shape of the fitted spectrum until the temperature value that best matches the experimental spectrum is determined. This method is mainly used when the spectral resolution is low and the fine structure of the spectrum cannot be observed. Since most spectral instruments cannot meet high spectral resolution, the fitted spectrum temperature measurement method is widely used.

[0004] There are many issues that should be noted when using the Boltzmann diagram slope temperature measurement method, such as the transition probability of the selected spectral line should have a reliable value, the spectral line should not be affected by self-absorption, and the excitation energy difference of the spectral line group should be as large as possible. The intensity of the selected spectral line should be very sensitive to changes in the plasma temperature, etc. This method increases the amount of calculation, does not intuitively utilize the structural characteristics of the spectrum, and is inefficient; for the experimental spectrum and calculated spectrum fitting method, the vibrational temperature and rotational temperature are measured by comparing the software fitting spectrum with the experimental spectrum at a specific resolution. Although there is a certain guarantee in terms of accuracy, the comparison of each peak greatly increases the time consumption, and does not utilize the unique structural characteristics of the spectrum. In essence, it focuses on the comparison effect and does not consider the coupling mechanism of vibration-rotation transitions. Summary of the Invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to propose a method, system, equipment and storage medium for inverting the tail flame / shock wave vibration-rotation temperature based on the non-equilibrium OH spectrum, taking into account the local thermodynamic non-equilibrium state in the actual combustion process, based on the ultraviolet radiation spectrum of OH, and simultaneously measuring the rotational temperature and vibration temperature, making full use of the spectral characteristics of OH, greatly reducing the amount of calculation, and improving the measurement efficiency while ensuring the measurement accuracy.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, specifically comprising the following steps:

[0008] Step 1: Derive the formula for spectral line intensity under non-equilibrium state;

[0009] Step 2: Determine the vibration-rotation temperature inversion method of the tail flame;

[0010] Step 3: Based on the spectral line intensity formula under the local non-equilibrium thermodynamic state derived in Step 1, the temperature step length of the shock wave is determined by the temperature range of the shock wave and the change in the particle number distribution at high temperature;

[0011] Step 4: Determine the vibration-rotation temperature inversion method of the shock wave.

[0012] The specific method of step 1 is:

[0013] 1.1. Derivation of the distribution of particle numbers at each energy level under local thermodynamic non-equilibrium conditions.

[0014] N e 、N v 、N r are the particle population layouts of electronic, vibrational and rotational states, respectively, g e is the degeneracy of the electronic state, Q e , Q v , Q r are the partition functions of the electronic, vibrational and rotational states, respectively, E e 、E v 、E r are the energies of the electronic state, vibrational state, and rotational state, respectively, T e 、T v 、T r are the electronic temperature, vibrational temperature and rotational temperature respectively, k is the Boltzmann constant, and J' is the high-energy level rotational quantum number;

[0015] 1.2. The calculation formula for the particle population distribution at any vibrational-rotational energy level is obtained:

[0016] N v'J' =N0·N e ·N v ·N r

[0017]

[0018] N0 is the total number of molecules;

[0019] 1.3. The formula for calculating the spectral line intensity when a molecule transitions from a high energy level (v', J') to a low energy level (v", J") under local thermodynamic non-equilibrium conditions at arbitrary electronic, vibrational, and rotational temperatures is given:

[0020] represents the vibrational-rotational transition probability, represents the Henry-London factor, and c represents the speed of light.

[0021] The specific method of step 2 is:

[0022] 2.1. Based on the spectral line intensity formula under the local thermodynamic non-equilibrium state derived in step 1.3 of step 1, calculate the normalized spectrum of OH(AX) at different vibrational temperatures at a given rotational temperature;

[0023] 2.2. Based on the spectral line intensity formula under the local thermodynamic non-equilibrium state derived in step 1.3 of step 1, calculate the normalized spectrum of OH(AX) at different rotational temperatures at a given vibrational temperature;

[0024] 2.3. The rotational temperature of the tail plume is inferred using the relative intensities of the peaks of the tail plume that are sensitive to changes in rotational temperature. After determining the rotational temperature, the normalized OH(AX) spectra at different vibrational temperatures at that rotational temperature are calculated. The vibrational temperature of the tail plume is then inferred using the relative intensities of the peaks of the tail plume that are sensitive to changes in vibrational temperature.

[0025] 2.4. Draw a curve showing the relative intensity of the peak value of the tail flame characteristic that is sensitive to the rotation temperature and fitting it with a cubic function.

[0026] The specific method of step 4 is:

[0027] 4.1. Plot the reference peaks of the normalized OH(AX) spectrum at different temperatures and determine the temperature at which the reference peak changes.

[0028] 4.2. Inversion method for determining shock wave vibration-rotation temperature;

[0029] When the spectrum reference peak received by the instrument is the tail plume reference peak, the method for inverting the vibration-rotation temperature from the tail plume spectrum is used. When the spectrum reference peak received by the instrument is the shock wave reference peak, the shock wave vibration-rotation temperature inversion method is re-determined. Specifically, the resolution of the instrument is first determined, and the OH normalized spectra at different temperatures at the resolution are calculated. When the peak value of the shock wave reference peak is higher than the peak value of the tail plume reference peak, the shock wave vibration-rotation temperature inversion method is used.

[0030] 4.3. Determine the shock wave vibration-rotation temperature using the inversion method from step 4.2 and calculate the normalized spectra of OH(AX) at different rotational temperatures at a given vibration temperature.

[0031] 4.4. The variation pattern of the shock wave spectrum is consistent with that of the tail flame. The rotational temperature of the shock wave is inverted by selecting the relationship between the relative intensity of the shock wave characteristic peak that is sensitive to changes in rotational temperature and the rotational temperature. After determining the rotational temperature, the normalized OH(AX) spectrum at different vibrational temperatures under this rotational temperature is calculated. The vibrational temperature of the shock wave is then inverted using the relationship between the relative intensity of the shock wave characteristic peak that is sensitive to changes in vibrational temperature and the vibrational temperature.

[0032] 4.5. Draw a curve showing the change of the relative intensity of the shock wave characteristic peak that is sensitive to the rotation temperature and fit it with a cubic function.

[0033] A system for inverting tail plume / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, comprising:

[0034] Spectral line intensity calculation module under non-equilibrium state: according to the spectral line intensity calculation formula obtained in step 1, solve the OH (AX) normalized radiance under local thermodynamic non-equilibrium state;

[0035] The module for inversion of the tail flame's vibration-rotation temperature under non-equilibrium conditions: Based on the tail flame's vibration-rotation temperature inversion method determined in step 2, the module implements the inversion of the tail flame's vibration-rotation temperature under local thermodynamic non-equilibrium conditions.

[0036] Shock wave vibration-rotation temperature inversion method module under non-equilibrium state: Based on the shock wave vibration-rotation temperature inversion method determined in steps 3 and 4, the shock wave vibration-rotation temperature inversion under local thermodynamic non-equilibrium state is realized;

[0037] Verification module for the vibration-rotation temperature inversion method of tail flame / shock wave under non-equilibrium state: Based on the vibration-rotation temperature inversion method of tail flame / shock wave determined in steps 2 and 4, the inversion method of the vibration-rotation temperature of tail flame / shock wave under local thermodynamic non-equilibrium state is verified by verifying the radiance calculation of Atlas Booster and BSUV-2.

[0038] An electronic device for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, comprising:

[0039] Memory for storing computer programs;

[0040] A processor is used to implement the method of inverting the tail flame / shock wave vibration-rotation temperature based on the non-equilibrium OH spectrum when executing the computer program.

[0041] A computer-readable storage medium stores a computer program. When the computer program is executed by a processor, it can invert the tail flame / shock wave vibration-rotation temperature based on a non-equilibrium OH spectrum.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] (1) Based on the Boltzmann distribution law, the particle number distribution formula under the local thermodynamic non-equilibrium state is derived, and then the spectral line intensity formula under this state is derived.

[0044] (2) Previous studies focused on selecting the peak of the inversion rotation temperature of OH(AX) located in the 0-0 band or the peak of the inversion vibration temperature located in the 1-1 band; in steps 2 and 4 of the present invention, the rotation temperature is inverted using the peak of the 0-0 band, and the vibration temperature is inverted using the peak of the 1-1 band, and temperature inversion is performed in combination with the 0-0 band and the 1-1 band.

[0045] (3) Previous studies used two independent characteristic peaks to invert the vibrational temperature and the rotational temperature separately, and there was no connection between the two. The present invention first inverts the rotational temperature, and then uses the spectra of different vibrational temperatures under the rotational temperature to invert the vibrational temperature, combining the rotational temperature and the vibrational temperature together, which is consistent with the mechanism of vibration-rotation coupling transition.

[0046] (4) Previous studies did not carefully distinguish the temperature ranges of the tail flame and the shock wave, and the inverted temperature values ​​were usually below 10000K; the present invention provides a temperature inversion method suitable for the tail flame and the shock wave based on their different temperature ranges.

[0047] The present invention focuses on utilizing the structural characteristics of the spectrum, combining the peak of the inverted rotational temperature in the 0-0 band with the peak of the inverted vibrational temperature in the 1-1 band, thereby improving the utilization rate of the spectrum. In the temperature inversion process, the physical significance of the vibration-rotation coupling transition is taken into account, ensuring the calculation accuracy while also greatly improving the inversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 Flowchart of the present invention.

[0049] Figure 2 Normalized spectra of OH(AX) at different vibration temperatures (rotation temperature is 2000K).

[0050] Figure 3 Normalized spectra of OH(AX) at different rotation temperatures (vibration temperature is 2000K).

[0051] Figure 4 This is the curve of the relative intensity of the peak at 306.91nm changing with the rotation temperature.

[0052] Figure 5 This is the curve of the particle number density at different vibration energy levels changing with temperature.

[0053] Figure 6 is the reference peak of the OH(AX) normalized spectrum at different temperatures.

[0054] Figure 7 Normalized spectra of OH(AX) at different vibration temperatures (rotation temperature is 10000K).

[0055] Figure 8 Normalized spectra of OH(AX) at different rotation temperatures (vibration temperature is 10000K).

[0056] Figure 9 This is the curve of the relative intensity of the peak at 309.07nm changing with the rotation temperature.

[0057] Figure 10 is the ultraviolet radiation spectrum of Atlas Booster.

[0058] Figure 11 Normalized spectra of OH(AX) at different vibration temperatures (rotation temperature is 2494K).

[0059] Figure 12 This is the curve of the relative intensity of the peak at 312.34nm changing with the vibration temperature (the rotation temperature is 2494K).

[0060] Figure 13 is the ultraviolet radiation spectrum of BSUV-2.

[0061] Figure 14 is the normalized spectrum of OH(AX) at different vibration temperatures (rotation temperature is 7240K)

[0062] Figure 15 The curve of the relative intensity of the peak at 316.57nm changing with the vibration temperature (the rotation temperature is 7240K) DETAILED DESCRIPTION

[0063] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] Step 1: Derive the formula for spectral line intensity under non-equilibrium state:

[0065] 1.1. Derivation of the distribution of particle numbers at each energy level under local thermodynamic non-equilibrium conditions.

[0066] N e 、N v 、N r are the particle population layouts of electronic, vibrational and rotational states, respectively, g e is the degeneracy of the electronic state, Q e , Q v , Q r are the partition functions of the electronic, vibrational and rotational states, respectively, E e 、E v 、E r are the energies of the electronic state, vibrational state, and rotational state, respectively, T e 、T v 、T r are the electronic temperature, vibrational temperature and rotational temperature respectively, k is the Boltzmann constant, and J' is the high-energy level rotational quantum number.

[0067] 1.2. The calculation formula for the particle population distribution at any vibrational-rotational energy level is obtained:

[0068] N v'J' =N0·N e ·N v ·N r

[0069]

[0070] N0 is the total number of molecules.

[0071] 1.3. Finally, the formula for calculating the spectral line intensity when a molecule transitions from a high energy level (v', J') to a low energy level (v", J") under local thermodynamic non-equilibrium conditions at any electronic temperature, vibrational temperature, or rotational temperature is given: represents the vibrational-rotational transition probability, represents the Henry-London factor, and c represents the speed of light.

[0072] Step 2: Determine the inversion method of the vibration-rotation temperature of the tail flame:

[0073] 2.1. Based on the formula for spectral line intensity under the local thermodynamic non-equilibrium state derived in step 1.3 of step 1, the key calculation parameters vibration temperature and rotation temperature have different effects on the normalized radiance of the spectrum (although the electron temperature is also a key calculation parameter, since OH has only one electronic state transition, the electron temperature has no effect on the value of the normalized radiance, so the electron temperature is not considered). Combined with the fact that the temperature of the tail flame is around 3000K, we determine the vibration-rotation temperature inversion idea of ​​the tail flame by calculating the normalized radiance spectra at different vibration temperatures and rotation temperatures. First, calculate the spectra at different vibration temperatures at a given rotation temperature. Take the following calculation as an example: Based on Lifbase software, calculate the normalized radiance of OH (AX) in the 306nm-320nm band at 1 standard atmospheric pressure, a rotation temperature of 2000K, and a vibration temperature of 1000K-3400K (a step size of 300K). The reference peak is located at 309.07nm, and the instrument resolution is 0.2nm. Figure 2 As shown;

[0074] 2.2. Calculate the spectra at different rotational temperatures at a given vibrational temperature. Take the following calculation as an example: Based on Lifbase software, calculate the normalized radiance of OH(AX) in the 306nm-320nm band at 1 standard atmospheric pressure, a vibrational temperature of 2000K, and a rotational temperature of 1000K-3400K (step size of 300K). The reference peak is located at 309.07nm, and the instrument resolution is 0.2nm. Figure 3 As shown;

[0075] 2.3. By Figure 2 and Figure 3 By comparison, it was found that rotational temperature changes the spectrum of the entire band, but vibrational temperature only changes the spectrum of the 312.34nm-320nm band. Therefore, the rotational temperature of the tail flame is inverted using the relative intensity of the peak at 306.91nm. After determining the rotational temperature, the normalized radiance spectrum of different vibration temperatures under the rotational temperature is calculated, and the vibration temperature of the tail flame is inverted using the relative intensity of the peak at 312.34nm.

[0076] 2.4. The relative intensity of the peak at 306.91 nm versus the rotation temperature was plotted using Origin software, and the cubic function y = -2.611 × 10 -12 x 3 +1.605×10 -8 x 2 -3.294×10 -4 x-0.01662 fitting, such as Figure 4 .

[0077] Step 3: Figure 5The curves of the distribution of particle numbers at the 0-8 vibrational energy levels versus temperature show that: as the temperature increases, the curves of the distribution of particle numbers at each energy level tend to be flat. According to the spectral line intensity formula under the local non-equilibrium thermodynamic state derived in step (1), the corresponding trend of change in normalized radiance is no longer obvious. Considering that the temperature range of the shock wave is large (3000K-25000K) and the particle number distribution changes less at high temperatures, in order to present a clearer spectral change pattern, the temperature step of the shock wave is determined to be 2000K.

[0078] Step 4: Determine the vibration-rotation temperature inversion method of the shock wave:

[0079] 4.1. Based on the reference peak diagram of the OH(AX) normalized spectrum at different temperatures drawn by Lifbase, the temperature value when the position of the reference peak changes can be determined, such as Figure 6 , determining that the position of the reference peak changes from 309.07 nm to 306.91 nm after 6150 K; (the specific temperature value will change according to the resolution of the simulated spectrum. The resolution used in the present invention is 0.095 nm. The reference peak at this resolution changes when the temperature is higher than 6150 K);

[0080] 4.2. Since the temperature range of the shock wave is 3000K-25000K, and the reference peak changes after the temperature is higher than a certain temperature value, the temperature value determined by the resolution used in the present invention is 6150K. Therefore, the shock wave spectrum of 3000K-6150K can use the method of inverting the vibration-rotation temperature of the tail flame spectrum. After the reference peak changes (the temperature is higher than 6150K), the inversion method of the shock wave vibration-rotation temperature needs to be re-determined. Reducing the temperature step size can make the determined temperature more accurate. First, calculate the spectra of different vibration temperatures at a given rotation temperature. Take the following calculation as an example: Based on Lifbase software, calculate the normalized radiant brightness of OH (AX) in the 306nm-320nm band at 1 standard atmospheric pressure, with a rotation temperature of 10000K and a vibration temperature of 7000K-19000K. The reference peak is located at 306.91nm, and the instrument resolution is 0.095nm. Figure 7 ;

[0081] 4.3. Calculate the spectra at different rotational temperatures at a given vibrational temperature. Take the following calculation as an example: Based on Lifbase software, calculate the normalized radiance of OH(AX) in the 306nm-320nm band at 1 standard atmospheric pressure, with a vibrational temperature of 10000K and a rotational temperature of 7000K-19000K. The reference peak is located at 306.91nm, and the instrument resolution is 0.095nm. Figure 8 ;

[0082] 4.4. By Figure 7 and Figure 8 By comparison, it was found that the higher temperature of the shock wave caused the reference peak to change, but the change pattern of the spectrum was consistent with that of the tail flame. The rotational temperature of the shock wave was inverted by selecting the relationship between the relative intensity of the peak at 306.91nm and the rotational temperature. After determining the rotational temperature, the normalized radiance spectrum of different vibration temperatures at this rotational temperature was calculated. The vibration temperature of the shock wave was then inverted using the relationship between the relative intensity of the peak at 316.57nm and the vibration temperature.

[0083] 4.5. The relative intensity of the peak at 309.07 nm versus the rotation temperature was plotted using Origin software, and the cubic function y = -1.20771 × 10 -13 x 3 +6.11373×10 -9 x 2 -1.07773×10 -4 x+1.4365 fitting, such as Figure 9 .

[0084] Next, the temperature inversion method of the tail flame is verified by Atlas Booster; the temperature inversion method of the shock wave is verified by BSUV-2.

[0085] 1. Verify the vibration-rotation temperature inversion method of the tail plume using Atlas Booster:

[0086] 1). Verify the tail plume temperature inversion method proposed in step 2. Degenerate the flow field state of OH from the local thermodynamic non-equilibrium state to the local thermodynamic equilibrium state (rotational temperature = vibrational temperature = electron temperature = translational temperature). Invert the vibrational temperature and rotational temperature based on the OH radiance spectrum calculated from the experimental data. Calculate the relative error to verify the inversion method of the tail plume's vibration-rotational temperature. Take the following verification as an example: Using the HITRAN database, based on the AtlasBooster flight parameters (speed is 2930m / s) and flow field data (temperature is 2380K, pressure is 78410Pa, OH concentration is 0.00325), the ultraviolet radiance of OH in the Atlas Booster tail plume is calculated. Figure 10 ;

[0087] 2). Using the tail flame temperature inversion method proposed in step 2, the rotation temperature is first inverted based on the OH radiance spectrum calculated based on experimental data: Figure 10 The ratio of the peak value of the tail flame characteristic peak at 306.91nm to the peak value of the tail flame reference peak at 309.07nm is 0.6645. Substituting it into the cubic equation of the relative intensity of the peak at 306.91nm with respect to the rotation temperature, y = -2.611×10 -12 x 3 +1.605×10-8 x 2 -3.294×10 -4 In x-0.01662, the rotation temperature of the Atlas Booster tail flame is 2494K, while the theoretical rotation temperature is 2380K, so the relative error of the measurement is 4.8%;

[0088] 3). According to the calculation formula of the spectral line intensity under the local thermodynamic non-equilibrium state derived in step 1, the normalized radiance of different vibrational temperatures when the rotational temperature is 2494K is calculated based on the Lifbase software. Take the following calculation as an example: Under 1 standard atmospheric pressure, the normalized radiance of OH(AX) with a rotational temperature of 2494K and a vibrational temperature of 1000K-3400K in the 306nm-320nm band is calculated. The reference peak is located at 309.07nm, and the instrument resolution is 0.2nm. Figure 11 ;

[0089] 4). Based on the normalized spectra of OH(AX) at different vibration temperatures calculated in the previous step, the curve of the relative intensity of the peak value of the tail flame characteristic peak at 312.34nm versus the vibration temperature (rotation temperature is 2494K) is plotted using Origin software, as shown below: Figure 12 and use the cubic function y = -3.49×10 -12 x 3 +2.462×10 -8 x 2 -1.338×10 -5 x+0.3079 fit;

[0090] 5). Confirmed Figure 10 The ratio of the peak value of the tail flame characteristic at 312.34nm to the peak value of the reference tail flame at 309.07nm is 0.3755. Substituting this into the cubic equation of the relative intensity of the peak at 312.34nm with respect to the rotation temperature, the vibration temperature of the AtlasBooster tail flame is inferred to be 2538K. The theoretical vibration temperature is 2380K, so the relative error of the measurement is 6.6%.

[0091] 2. Verify the vibration-rotation temperature inversion method of shock waves using BSUV-2:

[0092] 1) Verify the shock wave temperature inversion method proposed in step 4, degenerate the flow field state where OH is located from the local thermodynamic non-equilibrium state to the local thermodynamic equilibrium state (rotational temperature = vibrational temperature = electron temperature = translational temperature), invert the vibrational temperature and rotational temperature based on the OH radiance spectrum calculated from the experimental data, calculate the relative error, and verify the vibration-rotation temperature inversion method of the shock wave. Take the following verification as an example: Using the HITRAN database, based on the flight parameters of BSUV-2 (speed is 5100m / s) and flow field data (temperature is 7500K, pressure is 5.1085884atm, OH concentration is 2×10-10), the ultraviolet radiance of OH in the BSUV-2 shock wave is calculated, as shown in the figure. Figure 13 ;

[0093] 2) Using the shock wave temperature inversion method proposed in step 4, the rotation temperature is first inverted based on the radiation spectrum calculated based on the experimental data, and the Figure 13 The ratio of the peak value of the shock wave characteristic peak at 309.07 nm to the peak value of the shock wave reference peak at 306.91 nm is 0.931. Substituting it into the cubic equation of the relative intensity of the peak at 309.07 nm with respect to the rotation temperature, y = -1.20771×10 -13 x 3 +6.11373×10 -9 x 2 -1.07773×10 -4 At x+1.4365, the rotation temperature of the BSUV-2 shock wave is inverted to be 7240K. The theoretical rotation temperature is 7500K, so the relative error of the measurement is 3.5%;

[0094] 3) According to the calculation formula of the spectral line intensity under the local thermodynamic non-equilibrium state derived in step 1, calculate the normalized radiance of different vibration temperatures when the rotation temperature is 7240K. Take the following calculation as an example: Based on Lifbase software, calculate the normalized radiance of OH(AX) in the 306nm-320nm band at 1 standard atmospheric pressure with a rotation temperature of 7240K and a vibration temperature of 7000K-19000K. The reference peak is located at 306.91nm, and the instrument resolution is 0.095nm. Figure 14 ;

[0095] 4) Based on the normalized spectra of OH(AX) at different vibration temperatures calculated in the previous step, the relative intensity of the peak value of the shock wave characteristic peak at 316.57nm is plotted as a function of the vibration temperature (the rotation temperature is 7240K), as shown in the figure. Figure 15 , and use the cubic function y = 4.33889 × 10 -14 x 3 -2.31225×10 -9 x 2+4.63209×10 -5 x+0.22975 fit;

[0096] 5) Confirmed Figure 13 The ratio of the shock wave characteristic peak-to-peak value at 316.57nm to the shock wave reference peak-to-peak value at 306.91nm is 0.471. Substituting this into the cubic equation of the relative intensity of the shock wave reference peak-to-peak value at 316.57nm with respect to the rotational temperature, the vibration temperature of the BSUV-2 shock wave is inferred to be 7805K. The theoretical vibration temperature is 7500K, so the relative error of the measurement is 4.1%.

[0097] By inverting the vibration-rotation temperature of the tail flame and shock wave under local thermodynamic equilibrium and performing error analysis, the correctness of the vibration-rotation temperature inversion of the tail flame and shock wave under local thermodynamic non-equilibrium state is verified, and it is shown that this method is suitable for temperature inversion and early warning detection of the tail flame and shock wave of hypersonic aircraft.

[0098] The above description is only a specific example of the present invention and does not constitute any limitation to the present invention. Obviously, after understanding the content and principles of the present invention, professionals in this field may make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are within the scope of protection of the claims of the present invention.

Claims

1. A method for inverting the tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, characterized by comprising the following steps: Step 1: Derive the formula for spectral line intensity under non-equilibrium state; 1.

1. Derivation of the distribution of particle numbers at each energy level under local thermodynamic non-equilibrium conditions. N e 、N v 、N r are the particle population layouts of electronic, vibrational and rotational states, respectively, g e is the degeneracy of the electronic state, Q e , Q v , Q r are the partition functions of the electronic, vibrational and rotational states, respectively, E e 、E v 、E r are the energies of the electronic state, vibrational state, and rotational state, respectively, T e 、T v 、T r are the electronic temperature, vibrational temperature and rotational temperature respectively, k is the Boltzmann constant, and J' is the high-energy level rotational quantum number; 1.

2. The calculation formula for the particle population distribution at any vibrational-rotational energy level is obtained: A v'J' =N0·N e ·A v ·A r N0 is the total number of molecules; 1.

3. The formula for calculating the spectral line intensity when a molecule transitions from a high energy level (v', J') to a low energy level (v", J") under local thermodynamic non-equilibrium conditions at arbitrary electronic, vibrational, and rotational temperatures is given: represents the vibrational-rotational transition probability, represents the Henry-London factor, c represents the speed of light; Step 2: Determine the vibration-rotation temperature inversion method of the tail flame; 2.

1. Based on the spectral line intensity formula under the local thermodynamic non-equilibrium state derived in step 1.3 of step 1, calculate the normalized spectrum of OH(AX) at different vibrational temperatures at a given rotational temperature; 2.

2. Based on the spectral line intensity formula under the local thermodynamic non-equilibrium state derived in step 1.3 of step 1, calculate the normalized spectrum of OH(AX) at different rotational temperatures at a given vibrational temperature; 2.

3. The rotational temperature of the tail plume is inferred using the relative intensities of the peaks of the tail plume that are sensitive to changes in rotational temperature. After determining the rotational temperature, the normalized OH(AX) spectra at different vibrational temperatures at that rotational temperature are calculated. The vibrational temperature of the tail plume is then inferred using the relative intensities of the peaks of the tail plume that are sensitive to changes in vibrational temperature. 2.

4. Plot the curve of the relative intensity of the peak value of the tail flame characteristic, which is sensitive to the rotation temperature, as a function of the rotation temperature and fit it with a cubic function; Step 3: Based on the spectral line intensity formula under the local non-equilibrium thermodynamic state derived in Step 1, the temperature step length of the shock wave can be determined by the temperature range of the shock wave and the change in the particle population distribution at high temperature, thereby presenting a clearer spectral variation pattern; Step 4: Determine the vibration-rotation temperature inversion method of the shock wave.

2. The method for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum according to claim 1, characterized in that the specific method of step 4 is: 4.

1. Plot the reference peaks of the normalized OH(AX) spectrum at different temperatures and determine the temperature at which the reference peak changes. 4.

2. Inversion method for determining shock wave vibration-rotation temperature; When the spectrum reference peak received by the instrument is the tail plume reference peak, the method for inverting the vibration-rotation temperature from the tail plume spectrum is used. When the spectrum reference peak received by the instrument is the shock wave reference peak, the shock wave vibration-rotation temperature inversion method is re-determined. Specifically, the resolution of the instrument is first determined, and the OH normalized spectra at different temperatures at the resolution are calculated. When the peak value of the shock wave reference peak is higher than the peak value of the tail plume reference peak, the shock wave vibration-rotation temperature inversion method is used. 4.

3. Determine the shock wave vibration-rotation temperature using the inversion method from step 4.2 and calculate the normalized spectra of OH(AX) at different rotational temperatures at a given vibration temperature. 4.

4. The variation pattern of the shock wave spectrum is consistent with that of the tail flame. The rotational temperature of the shock wave is inverted by selecting the relationship between the relative intensity of the shock wave characteristic peak that is sensitive to changes in rotational temperature and the rotational temperature. After determining the rotational temperature, the normalized OH(AX) spectrum at different vibrational temperatures under this rotational temperature is calculated. The vibrational temperature of the shock wave is then inverted using the relationship between the relative intensity of the shock wave characteristic peak that is sensitive to changes in vibrational temperature and the vibrational temperature. 4.

5. Draw a curve showing the variation of the relative intensity of the shock wave characteristic peak that is sensitive to the rotational temperature with the rotational temperature, and use a cubic function to fit it to complete the vibration-rotation temperature inversion method of the shock wave.

3. A system for inverting tail plume / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, used in the method according to any one of claims 1 or 2, characterized in that: include: Spectral line intensity calculation module under non-equilibrium state: according to the spectral line intensity calculation formula obtained in step 1, solve the OH (AX) normalized radiance under local thermodynamic non-equilibrium state; The module for inversion of the tail flame's vibration-rotation temperature under non-equilibrium conditions: Based on the tail flame's vibration-rotation temperature inversion method determined in step 2, the module implements the inversion of the tail flame's vibration-rotation temperature under local thermodynamic non-equilibrium conditions. Shock wave vibration-rotation temperature inversion method module under non-equilibrium state: Based on the shock wave vibration-rotation temperature inversion method determined in steps 3 and 4, the shock wave vibration-rotation temperature inversion under local thermodynamic non-equilibrium state is realized; Verification module for the vibration-rotation temperature inversion method of tail flame / shock wave under non-equilibrium state: Based on the vibration-rotation temperature inversion method of tail flame / shock wave determined in steps 2 and 4, the inversion method of the vibration-rotation temperature of tail flame / shock wave under local thermodynamic non-equilibrium state is verified by verifying the radiance calculation of Atlas Booster and BSUV-2.

4. An electronic device for inverting tail flame / shock wave vibration-rotation temperature based on non-equilibrium OH spectrum, used in the method according to any one of claims 1 or 2, characterized in that: include: Memory for storing computer programs; A processor is configured to implement the method for inverting the tail flame / shock wave vibration-rotation temperature based on the non-equilibrium OH spectrum as described in claim 1 or 2 when executing the computer program.

5. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, which, when executed by a processor, can invert the tail flame / shock wave vibration-rotation temperature according to the method for inverting the tail flame / shock wave vibration-rotation temperature based on the non-equilibrium OH spectrum according to any one of claims 1 or 2.

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