Numerically Simulation Of Nonequilibrium Flow And Optical Radiation Characteristic Of Hypersonic Vehicle

The study of high-temperature thermo-chemical nonequilibrium flow and radiation phenomena is the main content of high temperature gas dynamics and aerodynamic thermophysics which play an impontant role in hypersonic vehicle thermal protection, target detection and recognition, optical diagnostication of non-equilibrium effects of high temperature and high enthalpy flow.The goal of this paper is to numerically simulated the hypersonic flow field and radiation characteristics on the basis of the released relative studies. The main work is divided into two steps: Firstly, the flow field(no ionizing and weakly ionized) around the vehicle is simulated based on FASTRAN software, the effects of different chemical reaction models on the nonequilibrium characteristics of flow field around hypersonic vehicle are particularly anylized, and flow field data of different flight conditions are obtained as well; Secondly, according to ultraviolet, infrared radiation mechanism of the shock layer and wake flow field, the radiation intensity and radiance of the spatial, spectral distribution characteristics of different flow fields are theoretically calculated in the 0.2-0.4 micron and 2.0-5.0 micron spectral range to provide a basis for the related engineering applications. The main work including:(1) Simulation of thermochemical nonequilibrium flow field around hypersonic vehicle using FASTRANBased on the FASTRAN , using finite-rate chemical reaction model and the energy relaxation model, nonequilibrium flow field of RAM_CII experimental blunt cone model and Lobb sphere model are simulated and analized respectively, the effects of the chemical kinetics model, ionization or non- ionization,fluid viscosity and other factors on the nonequilibrium characteristic parameters(temperature, composition, pressure, surface heat, shock wave detached distance, etc.)of overall flow field are investigated.(2) Simulation of optical radiative characteristics of nonequilibrium flow field around RAM-CII vehicleThe RAM-CII vehicle flow field data on different heights and different flight Mach conditions are obtained using FASTRAN. According to ultraviolet, infrared radiation mechanisms of the shock layer and wake flow field, using line-by-line method and the LOS model, the spatial, spectral distribution characteristics of radiation intensity and radiance of the overall flow field in 0.2-0.4 micron and 2.0-5.0 micron spectral range are calculated.