球谐函数法求解辐射传输方程的假散射和射线效应  

False Scattering and Ray Effect in Spherical Harmonics Approximation for the Radiative Transfer Equation

作　　者：张昊春[1] 易红亮[1] 谈和平[1] 

机构地区：[1]哈尔滨工业大学能源科学与工程学院,黑龙江哈尔滨150001

出　　处：《计算物理》2006年第2期237-242,共6页Chinese Journal of Computational Physics

基　　金：国家自然科学基金重点项目(No.50336010);国家重点基础研究(973)专项经费(No.2003CB214500)资助项目

摘　　要：假散射和射线效应是辐射传输方程近似解法中出现的特有误差.从辐射传输方程的近似求解过程出发,在定性分析的基础上构造物理模型,通过数值模拟研究球谐函数法(P1和P3近似法)的假散射和射线效应.构造激光平行入射和倾斜入射二维半透明介质的物理模型,通过内部温度场的分布特征研究假散射.构造顶部侧面保持高温而其余侧面保持低温的二维半透明介质方案,通过对比底面边界净热流密度分析射线效应.计算结果表明球谐函数法中同时存在假散射和射线效应,P3近似比P1近似减小了射线效应.同时,球谐函数法的射线效应随光学厚度的增加而减小.The false scattering and ray effect in spherical harmonics method, including P1 and P3 approximation, isstudied. Physical models of parallel and oblique laser incidence into two-dimensional gray media are constructed and the temperature profile within the medium is investigated to examine the false scattering. The ray effect is analyzed by the net radiative flux in the boundary. Simulation resuhs show that both false scattering and ray effect exist in the spherical harmonics method, and the ray effect is mitigated higher in P3 than that in P1 approximation. In addition, the ray effect in the spherical harmonics approximation mitigates with increasing optical thickness within gray medium.

关 键 词：球谐函数法 假散射 射线效应 

分 类 号：TK124[动力工程及工程热物理—工程热物理]