非线性散射介质内辐射传递的积分矩方法

Integral moment method for radiative transfer in nonlinear scattering medium

提出了求解非线性散射介质内辐射传递的积分矩方法.将辐射传递方程中散射相函数的积分项转化为辐射强度各阶矩的线性组合.散射相函数为勒让德多项式展开形式,辐射强度矩的最高阶数与散射相函数的展开项数相同.将原本复杂的积分微分方程转化为微分方程,通过积分法求解此方程.积分矩方法不需要对立体角进行离散,不会引起射线效应.积分矩方法的计算结果与其他数值方法符合得很好,具有很高的计算精度.同时,在较少计算网格数的条件下,仍然可以得到较为满意的结果.

The integral moment method was proposed to solve radiative transfer in nonlinear scattering medium.In this method,the integral term of the scattering phase function was deduced to linear combinations of radiative intensity moments.The scattering phase function was expressed as a truncated Legendre series and the highest order of radiative intensity moments was equal to the approximation order of the scattering phase function.Then,the integro-differential equation was reduced to differential equation,which is solved by integral method.Since it is not required to discretize the solid angle,the integral moment method will not suffer ray effects.The results by the present method are in good agreement with those in references and the method has a high accuracy.Furthermore,satisfied results also can be obtained even in the case of fewer computational meshes.