A Boundary Element Method for Solving Heat Radiation Problems
A boundary element method which can be used to solve heat radiation problems without internal cells is described in the assumptions of diffusive surfaces and no scattering mediums. Firstly, the radiative heat flux of surfaces can be written as a difference between the absorbed incoming radiation and emitted radiation over the entire hemisphere, and then replacing the radiation intensity incoming in a direction by a linear combination of the blackbody emissive power and radiative heat fluxes, and representing the emitted radiation using the blackbody emissive power. Consequently, radiative heat transfer equation, which concerning the blackbody emissive power and radiative heat fluxes is obtained. Then, a relationship between the infinitesimal solid angle and surface is introduced to convert the integrals over the solid angle in the equations governing the radiative transfer into integrals over the surface bounding the medium. For the transparent medium and isothermal gray medium, pure boundary integral equations can be obtained from the integral conversion. For the nonisothermal gray medium, line integrals exist within the boundary integrals. The line integrals are evaluated by approximating unknown functions using radial basis functions, and consequently, a pure boundary integral equations can be obtained. For the non-gray medium, band approximation is adopted and the equations about radiation are formulated for each spectral interval. 2D and 3D numerical examples are given to demonstrate the efficiency of the presented method.
heat radiation participating medium diffusive surface boundary element method
J.Wang X.W.Gao
Department of Engineering Mechanics,Southeast University,Nanjing,210096,China;School of Aeronautics School of Aeronautics and Astronautics,Dalian University of Technology,Dalian,116024,China
国际会议
南京
英文
1-10
2009-10-18（万方平台首次上网日期，不代表论文的发表时间）