The Thermal Radiation Model Building And Emulation Of Optical Dome In Aerodynamic Thermal Environment

With the advent of a new era of military technology revolution in modern times, it is necessary and inevitable to equip high-speed precise guided aero crafts with infrared imaging detecting and tracking guidance technique. As high-speed aero crafts with optical imaging detecting system fly in the atmosphere, severe aero-optical effect is incurred by the intense interaction between its optical dome and the atmosphere. During the process, the radiation effect of optical dome and shock wave influence the imaging system severely. So the image quality of the aero-crafts optical imaging detecting system is impaired and thus the guidance precision will decrease.Aimed at studying optical dome radiation effect under the circumstances of aerodynamic heat, this paper showed the distribution of radiant energy on the infrared detector. The final result was based on the modeling and stimulation of the radiative transfer in the dome and the analysis of the radiative transfer process in the optical system by obtaining the marginal heat flux.The model of radiative heat transfer in optical dome was established on the process of coupled radiative and conductive heat transfer. Radiative transfer equation and conductive energy equation were formulated according to the division of space and angel of the dome. And the radiative transfer in the dome was calculated by means of finite volume method under the rectangular coordinate system. Meanwhile, the radiative temperature field of the dome was obtained by introducing the radiative heat flux as radiative heat source into the conductive energy equation. The iteration into radiative and conductive equation till the convergences of the radiative temperature field, finally solved radiative heat flux inside the dome.Backward Monte Carlo Method was applied to model the radiation transmission in optical system by tracing scales of rays and simulating interaction between rays and optical elements. At the same time the ray-tracing programs were also programmed in Visual C++ 6.0, which gave the radiative exchange factor and radiative energy distributions on infrared detector.The analysis of the stimulation result in this paper indicates that the model of radiative heat transfer in the dome and the optical system is feasible.