An engineering and numerical combined light environment design method

Abstract

A method for designing a light environment that combines engineering and numerical methods includes: conducting three-dimensional thermochemical nonequilibrium flow field numerical calculations; selecting typical observation windows and generating observation rays passing through the flow field region; interpolating the results of the three-dimensional thermochemical nonequilibrium flow field numerical calculations onto the observation rays to obtain density and temperature data on different observation rays; calculating the high-temperature gas emission coefficient at each point on the observation rays based on the engineering calculation formula for high-temperature gas radiation in the visible light band; and obtaining the background flow field light radiation intensity value I at each point on the optical path reaching the optical window by integrating along the observation ray path. sim Using optical environment measurement data from previous flight tests, the simulated value I of the background flow field light radiation intensity reaching the optical window at each point on the optical path was obtained through the aforementioned method. sim0 , and the measured value I exp By comparison, the light environment simulation correction factor f = I is obtained. exp / I sim0 Multiply the light environment simulation correction factor by the background flow field light radiation intensity value I of the optical window. sim This is the result of the lighting environment design.

Description

Technical Field

[0001] This invention relates to a light environment design method that combines engineering and numerical methods. It can be used for the simulation and design of the light environment of complex flow fields at the tail of high-speed aircraft and belongs to the field of overall design of high-speed aircraft. Background Technology

[0002] As the range increases, the positioning error of inertial navigation accumulates over time. Adopting a combined navigation approach based on star sensors and inertial systems can significantly improve strike accuracy. However, for near-space high-speed vehicles, the surrounding gas is subjected to intense compression and a rapid temperature increase, resulting in complex polymorphic particle composition. Under high-temperature conditions, a large number of high-energy states of these polymorphic particles are successively excited, causing self-luminous radiation in the surrounding gas flow field, creating background interference for star detection. In engineering, considering various factors, star sensors are generally installed at the bottom of the vehicle. However, the strong expansion and non-equilibrium complex flow field at the bottom is extremely complex. Numerical simulation requires a three-dimensional high-temperature non-equilibrium / radiation coupled model, which involves large computational loads, long cycles, and is extremely difficult to accurately predict. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a light environment design method that combines engineering and numerical methods. This method improves computational efficiency and can integrate flight test light environment data for rapid correction.

[0004] The technical solution of this invention is: Firstly, it provides a method for designing a lighting environment that combines engineering and numerical methods, wherein:

[0005] S1. For typical flight conditions within the optical detection segment of the flight trajectory, based on the altitude, speed and angle of attack of the typical flight conditions, conduct three-dimensional thermochemical non-equilibrium flow field numerical calculations.

[0006] S2. Based on the optical detection field of view, select a typical observation window within the detection field of view, and generate observation rays in all directions with the center of the observation window as the origin, so that the observation rays pass through the flow field region in S1.

[0007] S3. Interpolate the numerical calculation results of the three-dimensional thermochemical non-equilibrium flow field obtained in S1 onto the observation ray in S2 to obtain density and temperature data on different observation rays.

[0008] S4. Based on the density and temperature data at each point along the observed ray, and using the high-temperature gas visible light band radiation engineering calculation formula, calculate the high-temperature gas emission coefficient J at each point along the observed ray. ω ;

[0009] S5. Based on the high-temperature gas emission coefficient obtained in S4 at each point on the optical path, the background flow field light radiation intensity value I at each point on the optical path reaching the optical window is obtained by integrating along the observation ray path. sim ;

[0010] S6. Using the optical environment measurement data from previous flight tests, calculate the simulated value I of the background flow field light radiation intensity at each point on the optical path leading to the optical window using the methods in S1 to S5. sim0 The measured value of background flow field light radiation intensity I obtained during the flight test at that time was... exp By comparison, the light environment simulation correction factor f = I is obtained. exp / I sim0 ;

[0011] S7. Multiply the light environment simulation correction factor obtained in S6 by the background flow field light radiation intensity value I of the optical window obtained in S5. sim It is applied as a result of lighting environment design.

[0012] Preferably, when selecting a typical observation window within the detection field of view, it should include the direction of the central optical axis as well as different pitch angles and circumferential angles.

[0013] Preferably, the high-temperature gas emission coefficient J at each point on the observed ray is calculated. ω Specifically:

[0014] J ω =k p B ω

[0015] in,

[0016]

[0017] k p ρ represents the emission coefficient scaling factor, ρ represents the flow field temperature, ρ0 represents the atmospheric density at sea level, and T represents the flow field temperature.

[0018] B ω λ represents the blackbody radiation coefficient, ω represents the wave number, h represents Planck's constant, c represents the speed of light, λ represents the wavelength, and k represents Boltzmann's constant.

[0019] Preferably, the background flow field light radiation intensity value I at each point on the optical path reaching the optical window sim for:

[0020] I sim =∫0 l J ω dl

[0021] Where l is the distance from a point on the observation ray to the observation origin.

[0022] Secondly, a light environment design system combining engineering and numerical methods is provided, including: a three-dimensional thermochemical non-equilibrium flow field numerical calculation module, an observation ray generation module, an interpolation solution module, a high-temperature gas emission coefficient calculation module, a background flow field light radiation intensity value calculation module, a light environment simulation correction factor calculation module, and a light environment design result generation module; wherein:

[0023] The three-dimensional thermochemical non-equilibrium flow field numerical calculation module performs three-dimensional thermochemical non-equilibrium flow field numerical calculations for typical flight states within the optical detection section of the flight trajectory, based on the altitude, speed and angle of attack of the typical flight states, and sends the results to the interpolation solution module.

[0024] The observation ray generation module selects a typical observation window within the optical detection field of view based on the optical detection field of view, and generates observation rays in all directions with the center of the observation window as the origin. This allows the observation rays to pass through the flow field region set in the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, and sends the observation ray information in each direction to the interpolation solution module.

[0025] The interpolation module interpolates the numerical calculation results of the three-dimensional thermochemical non-equilibrium flow field obtained by the three-dimensional thermochemical non-equilibrium flow field numerical calculation module onto the observation ray obtained by the observation ray generation module, thereby obtaining density and temperature data on different observation rays.

[0026] The high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient J at each point on the observation ray based on the density and temperature data at each point along the ray and the high-temperature gas visible light band radiation engineering calculation formula. ω And send it to the background flow field light radiation intensity value calculation module;

[0027] The background flow field light radiation intensity calculation module calculates the background flow field light radiation intensity value I at each point on the optical path by integrating the high-temperature gas emission coefficient obtained from the high-temperature gas emission coefficient calculation module along the observation ray path. sim And send it to the lighting environment design results generation module;

[0028] The optical environment simulation correction factor calculation module uses optical environment measurement data from previous flight tests, and calls upon the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, the observation ray generation module, the interpolation solution module, the high-temperature gas emission coefficient calculation module, and the background flow field optical radiation intensity value calculation module to calculate and obtain the simulated value I of the background flow field optical radiation intensity at each point on the optical path reaching the optical window. sim0 The measured value of background flow field light radiation intensity I obtained during the flight test at that time was... exp By comparison, the light environment simulation correction factor f = I is obtained.exp / I sim0 And send it to the lighting environment design results generation module;

[0029] The lighting environment design result generation module multiplies the lighting environment simulation correction factor obtained from the lighting environment simulation correction factor calculation module by the background flow field light radiation intensity value I of the optical window obtained from the background flow field light radiation intensity value calculation module. sim This is output as the result of the lighting environment design.

[0030] Preferably, when the observation ray generation module selects a typical observation window within the detection field of view, it should include the direction of the central optical axis as well as different pitch angles and circumferential angles.

[0031] Preferably, the high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient J at each point on the observation ray. ω Specifically:

[0032] J ω =k p B ω

[0033] in,

[0034]

[0035] k p ρ represents the emission coefficient scaling factor, ρ represents the flow field temperature, ρ0 represents the atmospheric density at sea level, and T represents the flow field temperature.

[0036] B ω λ represents the blackbody radiation coefficient, ω represents the wave number, h represents Planck's constant, c represents the speed of light, λ represents the wavelength, and k represents Boltzmann's constant.

[0037] Preferably, the background flow field light radiation intensity value calculation module calculates the background flow field light radiation intensity value I at each point on the optical path reaching the optical window. sim hour:

[0038] I sim =∫0 l J ω dl

[0039] Where l is the distance from a point on the observation ray to the observation origin.

[0040] Compared with the prior art, the present invention has the following advantages:

[0041] (1) The present invention adopts a light environment design method that combines engineering and numerical methods, which has high computational efficiency;

[0042] (2) This invention can integrate flight test light environment data to carry out rapid correction. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the optical detection device and optical path of the aircraft of the present invention. Detailed Implementation

[0044] To address the design challenges of the complex flow field optical environment at the tail of high-speed aircraft, this invention provides a method combining engineering and numerical methods for optical environment design. The key features of this method are: the integration of engineering and numerical methods, high computational efficiency, and the ability to incorporate flight test optical environment data for rapid correction.

[0045] 1. For typical flight conditions within the optical detection segment of the flight trajectory, the typical flight conditions should cover the characteristics of altitude and angle of attack changes. Based on the altitude, velocity and angle of attack of the typical flight conditions, conduct numerical calculations of the three-dimensional thermochemical non-equilibrium flow field.

[0046] 2. Based on the optical detection field of view, such as Figure 1 As shown, a typical observation window within the detection field of view is selected, which should include the direction of the central optical axis and different pitch and circumferential angles. With the center of the observation window as the origin, observation rays are generated in all directions so that the observation rays pass through the flow field region in step 1.

[0047] 3. Based on the flow field simulation results obtained in step 1, interpolate the three-dimensional thermochemical non-equilibrium flow field numerical simulation results onto the observation rays in step 2 to obtain density and temperature data on different observation rays.

[0048] 4. Based on the density and temperature data at each point along the observation ray obtained in step 3, and using the following engineering calculation formula for visible light radiation of high-temperature gas, calculate the high-temperature gas emission coefficient J at each point along the observation ray. ω .

[0049] J ω =k p B ω

[0050] in,

[0051]

[0052] k p ρ represents the emission coefficient scaling factor, ρ represents the flow field temperature, ρ0 represents the atmospheric density at sea level, and T represents the flow field temperature.

[0053] B ω λ represents the blackbody radiation coefficient, ω represents the wave number, h represents Planck's constant, c represents the speed of light, λ represents the wavelength, and k represents Boltzmann's constant.

[0054] 5. Based on the high-temperature gas emission coefficient at each point on the optical path obtained in step 4, the background flow field light radiation intensity at each point on the optical path reaching the optical window can be obtained by integrating along the observation ray path.

[0055]

[0056] Where l is the distance from a point on the observation ray to the observation origin, J ω Let be the emission coefficient at that point.

[0057] 6. Based on previous flight test optical environment measurement data, and according to the corresponding flight conditions, perform steps 1 to 5 to obtain the simulated value I of the background flow field optical radiation intensity under the flight test conditions. sim0 And compared with the measured value of background flow field light radiation intensity I obtained from the flight test. exp By comparison, the light environment simulation correction factor f = I is obtained. exp / I sim0 7. Multiply the light environment simulation correction factor obtained in step 6 by the background flow field light radiation intensity value I of the optical window obtained in step 5. sim It is applied as a result of lighting environment design.

[0058] Secondly, this invention provides a light environment design system combining engineering and numerical methods, comprising: a three-dimensional thermochemical non-equilibrium flow field numerical calculation module, an observation ray generation module, an interpolation solution module, a high-temperature gas emission coefficient calculation module, a background flow field light radiation intensity value calculation module, a light environment simulation correction factor calculation module, and a light environment design result generation module; wherein:

[0059] The three-dimensional thermochemical non-equilibrium flow field numerical calculation module performs three-dimensional thermochemical non-equilibrium flow field numerical calculations for typical flight states within the optical detection section of the flight trajectory, based on the altitude, speed and angle of attack of the typical flight states, and sends the results to the interpolation solution module.

[0060] The observation ray generation module selects a typical observation window within the optical detection field of view based on the optical detection field of view, and generates observation rays in all directions with the center of the observation window as the origin. This allows the observation rays to pass through the flow field region set in the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, and sends the observation ray information in each direction to the interpolation solution module.

[0061] The interpolation module interpolates the numerical calculation results of the three-dimensional thermochemical non-equilibrium flow field obtained by the three-dimensional thermochemical non-equilibrium flow field numerical calculation module onto the observation ray obtained by the observation ray generation module, thereby obtaining density and temperature data on different observation rays.

[0062] The high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient J at each point on the observation ray based on the density and temperature data at each point along the ray and the high-temperature gas visible light band radiation engineering calculation formula. ω And send it to the background flow field light radiation intensity value calculation module;

[0063] The background flow field light radiation intensity calculation module calculates the background flow field light radiation intensity value I at each point on the optical path by integrating the high-temperature gas emission coefficient obtained from the high-temperature gas emission coefficient calculation module along the observation ray path. sim And send it to the lighting environment design results generation module;

[0064] The optical environment simulation correction factor calculation module uses optical environment measurement data from previous flight tests, and calls upon the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, the observation ray generation module, the interpolation solution module, the high-temperature gas emission coefficient calculation module, and the background flow field optical radiation intensity value calculation module to calculate and obtain the simulated value I of the background flow field optical radiation intensity at each point on the optical path reaching the optical window. sim0 The measured value of background flow field light radiation intensity I obtained during the flight test at that time was... exp By comparison, the light environment simulation correction factor f = I is obtained. exp / I sim0 And send it to the lighting environment design results generation module;

[0065] The lighting environment design result generation module multiplies the lighting environment simulation correction factor obtained from the lighting environment simulation correction factor calculation module by the background flow field light radiation intensity value I of the optical window obtained from the background flow field light radiation intensity value calculation module. sim This is output as the result of the lighting environment design.

[0066] When selecting a typical observation window within the detection field of view, the observation ray generation module should include the direction of the central optical axis as well as different pitch angles and circumferential angles.

[0067] The high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient J at each point on the observed ray. ω Specifically:

[0068] J ω =k p B ω

[0069] in,

[0070]

[0071] k pρ represents the emission coefficient scaling factor, ρ represents the flow field temperature, ρ0 represents the atmospheric density at sea level, and T represents the flow field temperature.

[0072] B ω λ represents the blackbody radiation coefficient, ω represents the wave number, h represents Planck's constant, c represents the speed of light, λ represents the wavelength, and k represents Boltzmann's constant.

[0073] The background flow field light radiation intensity calculation module calculates the background flow field light radiation intensity value I at each point on the optical path reaching the optical window. sim hour:

[0074] I sim =∫0 l J ω dl

[0075] Where l is the distance from a point on the observation ray to the observation origin.

[0076] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. A method for designing a lighting environment that combines engineering and numerical methods, characterized in that... include: S1. For typical flight conditions within the optical detection segment of the flight trajectory, based on the altitude, speed and angle of attack of the typical flight conditions, conduct three-dimensional thermochemical non-equilibrium flow field numerical calculations. S2. Based on the optical detection field of view, select a typical observation window within the detection field of view, and generate observation rays in all directions with the center of the observation window as the origin, so that the observation rays pass through the flow field region in S1. S3. Interpolate the numerical calculation results of the three-dimensional thermochemical non-equilibrium flow field obtained in S1 onto the observation ray in S2 to obtain density and temperature data on different observation rays. S4. Based on the density and temperature data at each point along the observed ray, and using the engineering calculation formula for the visible light band radiation of high-temperature gas, calculate the emission coefficient of the high-temperature gas at each point along the observed ray. ; S5. Based on the high-temperature gas emission coefficient obtained in S4 at each point on the optical path, the background flow field light radiation intensity value reaching the optical window at each point on the optical path is obtained by integrating along the observation ray path. ; S6. Using the optical environment measurement data from previous flight tests, calculate the simulated value of the background flow field light radiation intensity at each point on the optical path leading to the optical window using the methods in S1~S5. Compared with the measured values ​​of background flow field light radiation intensity obtained during the flight test at that time, By comparison, the light environment simulation correction factor is obtained. ; S7. Multiply the light environment simulation correction factor obtained in S6 by the background flow field light radiation intensity value of the optical window obtained in S5. This is used as a result of lighting environment design; Calculate the high-temperature gas emission coefficient at each point on the observed ray. Specifically: in, This represents the emission coefficient scaling factor. Indicates the flow field temperature. This represents the atmospheric density at sea level. Indicates the flow field temperature; This represents the blackbody radiation coefficient. Indicates wave number, Denotes Planck's constant. Represents the speed of light. Indicates wavelength. This represents the Boltzmann constant.

2. The light environment design method combining engineering and numerical methods according to claim 1, characterized in that: When selecting typical observation windows within the detection field of view, the direction of the central optical axis and the directions of different pitch angles and circumferential angles should be included.

3. The light environment design method combining engineering and numerical methods according to claim 1, characterized in that: Background flow field light radiation intensity value at each point on the optical path reaching the optical window for: in This is the distance from a point on the observation ray to the observation origin.

4. A lighting environment design system that combines engineering and numerical methods, characterized in that... include: The system includes a three-dimensional thermochemical nonequilibrium flow field numerical calculation module, an observation ray generation module, an interpolation module, a high-temperature gas emission coefficient calculation module, a background flow field light radiation intensity calculation module, a light environment simulation correction factor calculation module, and a light environment design result generation module; among which: The three-dimensional thermochemical non-equilibrium flow field numerical calculation module performs three-dimensional thermochemical non-equilibrium flow field numerical calculations for typical flight states within the optical detection section of the flight trajectory, based on the altitude, speed and angle of attack of the typical flight states, and sends the results to the interpolation solution module. The observation ray generation module selects a typical observation window within the optical detection field of view based on the optical detection field of view, and generates observation rays in all directions with the center of the observation window as the origin. This allows the observation rays to pass through the flow field region set in the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, and sends the observation ray information in each direction to the interpolation solution module. The interpolation module interpolates the numerical calculation results of the three-dimensional thermochemical non-equilibrium flow field obtained by the three-dimensional thermochemical non-equilibrium flow field numerical calculation module onto the observation ray obtained by the observation ray generation module, thereby obtaining density and temperature data on different observation rays. The high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient at each point on the observed ray based on the density and temperature data at each point along the ray and the engineering calculation formula for high-temperature gas radiation in the visible light band. And send it to the background flow field light radiation intensity value calculation module; The background flow field light radiation intensity calculation module calculates the background flow field light radiation intensity value at each point on the optical path by integrating the high-temperature gas emission coefficient obtained from the high-temperature gas emission coefficient calculation module along the observation ray path. And send it to the lighting environment design results generation module; The optical environment simulation correction factor calculation module uses optical environment measurement data from previous flight tests, and calls upon the three-dimensional thermochemical non-equilibrium flow field numerical calculation module, the observation ray generation module, the interpolation solution module, the high-temperature gas emission coefficient calculation module, and the background flow field optical radiation intensity value calculation module to calculate and obtain the simulated value of the background flow field optical radiation intensity at each point on the optical path reaching the optical window. Compared with the measured values ​​of background flow field light radiation intensity obtained during the flight test at that time, By comparison, the light environment simulation correction factor is obtained. And send it to the lighting environment design results generation module; The lighting environment design result generation module multiplies the lighting environment simulation correction factor obtained from the lighting environment simulation correction factor calculation module by the background flow field light radiation intensity value of the optical window obtained from the background flow field light radiation intensity value calculation module. This is output as the result of the lighting environment design. The high-temperature gas emission coefficient calculation module calculates the high-temperature gas emission coefficient at each point on the observed ray. Specifically: in, This represents the emission coefficient scaling factor. Indicates the flow field temperature. This represents the atmospheric density at sea level. Indicates the flow field temperature; This represents the blackbody radiation coefficient. Indicates wave number, Denotes Planck's constant. Represents the speed of light. Indicates wavelength. This represents the Boltzmann constant.

5. The light environment design system combining engineering and numerical methods according to claim 4, characterized in that: When selecting a typical observation window within the detection field of view, the observation ray generation module should include the direction of the central optical axis as well as different pitch angles and circumferential angles.

6. The light environment design system combining engineering and numerical methods according to claim 4, characterized in that: The background flow field light radiation intensity calculation module calculates the background flow field light radiation intensity value reaching the optical window at each point on the optical path. hour: in This is the distance from a point on the observation ray to the observation origin.

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