A two-stage explicit/implicit approach combined with mixed finite element methods for a radiation-conduction model in optically thick anisotropic media
Eric Ngondiep
TL;DR
This paper introduces a three-dimensional nonlinear SP3 radiation–conduction model for optically thick, anisotropic media and develops a two-stage explicit/implicit predictor–corrector algorithm built on a mixed finite element discretization ($\mathcal{P}_{p}/\mathcal{P}_{p-1}/\mathcal{P}_{p-1}$). The method decouples time derivatives via a two-stage interpolation to yield a stable, high-accuracy scheme: a predictor step with explicit treatment and a corrector step with implicit treatment, analyzed under a time-step restriction. Theoretical results indicate spatial fourth-order and temporal second-order convergence in $L^2$-norm, complemented by numerical experiments across 3D examples that confirm stability and efficiency relative to existing approaches. These findings suggest the approach is well-suited for fast, accurate simulations of radiative-conduction processes in anisotropic media.
Abstract
This paper develops a two-stage explicit/impicit computational technique combined with a mixed finite element method for solving a nonlinear radiation-conduction problem in anisotropic media, subject to suitable initial and boundary conditions. The space derivatives are approximated by the mixed finite element method ($\mathcal{P}_{p}/\mathcal{P}_{p-1}/\mathcal{P}_{p-1}$), while the interpolation technique is employed in two stages to approximate the time derivative. The proposed strategy is so-called, a two-stage explicit/implicit computational technique combined with mixed finite element method. Specifically, the new algorithm should be observed as a predictor-corrector numerical scheme. Additionally, it efficiently treats the time derivative term and provides a necessary requirement on time step for stability. Under this time step limitation, the stability is deeply analyzed whereas the convergence order is numerically obtained in the $L^{2}$-norm. The theoretical results suggest that the developed approach is spatial fourth-order convergent and temporal second-order accurate. Some numerical experiments are carried out to confirm the theoretical results and to demonstrate the practical applicability of the new algorithm.
