Considering complexity of coupled fluid-solid calculation of low supersonic aircraft under unsteady flight condition, real time aerodynamic heat by outer fluid field is converted into floated third type boundary conditions for decoupled calculation. Take three-dimensional head cone experiencing accelerating diving as example, floated temperature and radiation equilibrium methods are adopted to extract surface heat transfer coefficients for decoupling calculation. Results are compared with coupled results to validate reliability of decoupling methods. It shows that with dispersed state points representing unsteady process, temperature distributions of cone surface at different state points by decoupling methods agree well with coupling ones. Calculating efficiency of decoupling methods is superior to coupling ones. Maximum relative errors of decoupling methods are both within 2%, even as external aerodynamic environment changes dramatically.

An evaporation model at steady state was bulit to analyse effect of solar radiation on evaporation of still water surface at low airflow velocity. It considers convective heat and mass transfer from water surface to airflow,interior heat transfer and solar radiation absorbing spectrum of water. Finite volume method combined with Monte Carlo method and spectral band model are used to simulate energy and mass transfer among water interior,surface and airflow. Effect of solar irradiance on evaporation rate of water surface was analysed at different airflow velocity,humidity,temperature,forward and inverse temperature difference. It shows that solar irradiance effect on evaporation of still water surface is great at low airflow velocity.

A technique combined domain decomposition and staged ray splitting is presented to decrease computational complexity by reducing surfaces and rays for intersections solution.Domain decomposition is based on relation between sub-zone and number of surfaces.Splitting ratio is determined with propagation information of stray light.A suppression structure and a multi-sensor system are analyzed.It shows that the technique can improve computational efficiency while maintaining acceptable accuracy.

According to the internal thermal emission of the medium,a new method,pseudo source adding method,is presented to analyze the apparent emissivities of semi-transparent medium layers.By this method,the apparent emissivity formulae are derived for two different cases,in one of which,the semi-transparent emitting surface is considered to be specularly reflecting,and the diffuse reflection is considered in the other.The substrate surface of the layer is supposed to be diffuse and opaque for the two cases.The comparison with the results by the Monte Carlo method is also given.

The Monte-Carlo method is applied to calculate the stray light of an infrared optical system.The system's geometrics tructure and the physical kinds of its elements are standardized.Some relevant probability models are established and a ray tracing approach is employed which can speed the calculation effectively.On the basis of those,an universal computer program is developed,and the stray light of an infrared camera has been analyzed.

Combined with the radiosity intensity of diffusely reflecting surfaces,the improved ray tracing method is reversely employed to analyze the apparent spectral emissivity of a body of semi-transparent medium having some diffuse surfaces.The radiosity intensities of a diffusely reflecting surface are obtainde by iteratively solving the energy balance equations of all discrete zones and using the ray tracing method reversley.The apparent emissivity results obtained by this method are separately compared with the exact solutions of the semi-transparent slabs and the numerical values of disc bodies of semi-transparent medium gained by Monte-Carlo method,and the apparent emissivity of a disc body is investigated.

Combined with spectral band model, control volume method and discrete transfer (DT) method are employed to investigate numerical calculation dealing with the transient combined radiation-conduction heat transfer in three dimensional cylindrical semi-transparent medium. The first and the third nonlinear boundary conditions are both considered. Compared with Zone method and improved Monte-Carlo approach, the calculated results by this method are reliable and more precise.