Simulation of rocket plume infrared images by computer programs is an important method to study their infrared radiation characteristics. In order to improve the computation efficiency, a simulation method based on CUDA was proposed. Firstly, the characteristics of the LOS (Line of Sight) method in radiative transfer calculation were analyzed. All the path points of LOS method were calculated in advance, and the parallel level was promoted to the number of path points of LOS method and bands of spectrum. In this case, more threads could be mobilized at the same time, and the utilization of GPU was improved. Secondly, A hardware bilinear interpolation method using CUDA texture memory was proposed, which greatly improved the calculation efficiency of physical parameters of the components. Finally, CUDA was also used for acceleration in the projection imaging module of spaceborne infrared sensor. The simulation results show that using CUDA for parallel computing to realize physical parameters search and projection imaging can greatly improve the overall simulation efficiency of rocket plume infrared images.
Photon is an ideal carrier of quantum information, which can carry spin angular momentum and orbital angular momentum. In recent years, orbital angular momentum has shown great application prospects in quantum communication, quantum radar and other fields. It has gradually become a research hotspot in the field of detection. It is necessary to calibrate and measure the orbital angular momentum before it is applied to the detection field. Based on the interference principle and aperture diffraction theory, the measurement of orbital angular momentum is realized indirectly, and the experimental platform is built to verify part of the simulation results. It provides technical support for the subsequent implementation of quantum detection technology.
In order to study the transmission characteristics of orbital angular momentum in the atmosphere, MATLAB software is used to simulate it. The power spectrum inversion method and subharmonic compensation theory are used to construct a random phase screen to simulate the atmospheric turbulence effect. The effects of different topological charges, turbulence intensity and transmission distance on the orbital angular momentum intensity, phase and spiral spectrum distribution are studied. It provides support for the new quantum detection technology.
In order to study the variation law of radiation characteristics of high temperature gas with altitude in medium and low altitude environment, the spectral radiation characteristics of three mixed gases containing H2O, CO2 and CO at different temperatures and pressures were calculated by LBL (Line by line) method, so as to analyze the corresponding changes of spectral radiation intensity of high temperature gas with the change of overall temperature and pressure, and explain the reason why the radiation spectrum changes with altitude. The results showed that the influence of temperature on the radiation intensity was more significant than that of pressure; at the same time, with the decrease of temperature, the peak value of spectral radiation gradually moved to the middle wave band, and the radiation intensity at 4.3 μm, which is the radiation band of CO2, and 4.7 μm, which is the radiation band of CO, gradually increased. However, due to the greater sensitivity of CO to the change of pressure, the relative radiation intensity at 4.7 μm after the pressure was reduced.
In order to study the infrared target characteristics of "low slow small" aircraft, the infrared target characteristics of six rotors unmanned aerial vehicle (UAV) are studied by numerical calculation. Considering the aerodynamic heating effect of rotor, and the radiation effect of the sun and the earth's atmosphere on the target, the changes of the target's radiation intensity in the three infrared bands of 1 ~ 3 μ m, 3 ~ 5 μ m, 8 ~ 12 μ m at night and in the daytime are studied under different observation angles. The results show that in the medium / long wave band, the target's infrared radiation mainly comes from the reflection of its own radiation and the earth's atmosphere, so its radiation characteristics change little in the daytime and at night, while for the short wave, the target's radiation intensity in the daytime is greater than that in the evening; the target's radiation intensity is directly related to the observation area, and the radiation intensity is the smallest in the positive and lateral observation, while the radiation intensity in the upward and The radiation intensity is the highest when looking down.
The measurement of radiant heat flux in flame tube is usually non-contact, so various factors should be considered in the actual measurement process. In order to improve the accuracy of measuring radiant heat flux on the inner wall of the flame tube, a flame tube model was used as the research object in this paper. A high temperature gas radiant heat flux wind tunnel measurement system was established to measure the wall radiant heat flux under different combustion conditions. The results of the test and numerical simulation were compared, and the relative error between the revised test and numerical simulation results was kept between -38.89% and 32.54%.
In order to study the infrared radiation characteristics of the solid rocket plume at high altitude, a numerical method is used to simulate the infrared spectral radiation intensity of a solid rocket plume at three altitudes, which are 120km, 150km and 180km, and the cause of the phenomenon is produced from the flow and radiation transmission views. It is confirmed that the peak value of infrared radiation intensity of the plume is within the range of 4~5 μm, due to the influence of high altitude diffusion effect. At the high altitude, the infrared radiation intensity of the plume increases rapidly at 4.7μm, which is at the CO absorption band. It can be within the same magnitude as the radiation intensity at the 4.3μm, which is at the CO2 absorption band. And the radiation intensity varies slowly with height, there is no severe fluctuation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.