Study Of Coupled Heat Transfer In Participating Medium Based On Ansys Or Fluent Mixed Programming

Radiation, conduction and convection are different kinds of physical phenomena in heat transfer. In not only the mathematical description but also physical meaning, there are fundamental differences. Generally, radiative heat transfer is usually associated with other heat transfer methods such as conduction, convection, phase transition in engineering applications. It is always correlated with other physical phenomena such as flow, chemical reactions, combustion. Therefore, the solution of coupled heat transfer problem is very important and has practical meaning. Due to the radiative transfer equation in absorbing-emitting-scattering media is an integral-differential equation, the complexity of the solution will increase with considering the complex geometry and coupled heat transfer.As Finite Volume Method (FVM) has clear physical meaning, there is a wide range of applications in the numerical calculation of flow and heat transfer. In the use of FVM for solving radiative transfer problems, it can not only ensure radiation energy conservation in each control volume, but also ensure radiation energy conservation in each control solid angle, which makes the simulation results having a high accuracy. Unstructured grid technology is an effective method to deal with complex geometry problems. So use Unstructured Finite Volume Method (U-FVM) model to deal with the radiative heat transfer problem can achieve both high accuracy and flexibility of treating complex geometry. At present, there are a lot of commercial softwares for analysis on conduction and flow, and they can achieve a certain degree of precision, what is more, they usually have their own development tools which can improve their functions using the mixed programming technique.The present thesis investigates and solves the following problem mainly:1. The model of the complex three-dimensional geometry in participatory media has been build, applied the theory of U-FVM on Cartesian coordinate system. I wrote corresponding Fortran programs and analysed several factors which affect the accuracy and efficiency of the programs'calculation.2. For the three-dimensional hollow ball coronary optical window model, which is in the aerodynamic heating environment. It is a radiative and conductive combined heat transfer problem. Applied the APDL, which is one of the development tools for ANSYS, and achieved mixed programming of Fortran (calculation of radiative heat source) and ANSYS (calculation of coupled heat transfer).3. For the tail plume of unmanned aerial vehicle model, which is a supersonic, high-altitude and remote aircraft. It is a coupled convection and radiation heat transfer problem. Applied the UDF, which is the development tool for Fluent, and achieved mixed programming of Fortran (calculation of radiative heat source) and Fluent (calculation of coupled heat transfer).