研究一维非平衡辐射扩散方程的数值方法.通过求解间断系数热传导方程的广义黎曼问题,得到一种带加权数值流量,基于该数值流量构造了一类新型的间断有限元方法.在时间离散上采用向后Euler方法,形成的非线性方程组采用Picard迭代求解.数值试验表明该方法具有捕捉大梯度的能力,而且能适应扩散系数间断的情形.
We discuss numerical simulation of one-dimensional non-equilibrium radiation diffusion equations. A weighted numerical flux between adjacent grid cells is obtained by solving heat conduction equation with discontinuous coefficient. With this numerical flux of diffusive generalized Riemann problem (dGRP) , a discontinuous finite element method is proposed for radiation diffusion equations. A backward Euler time discretization is applied for semi-discrete form and a Picard iteration is used to solve nonlinear system of equations. Numerical results demonstrate that the method has a capability of capturing strong gradients and can be accommodated to discontinuous diffusion coefficient.