Applied Numerical Mathematics ( IF 2.2 ) Pub Date : 2021-04-09 , DOI: 10.1016/j.apnum.2021.04.004 Lin Zhang , Yongbin Ge
In this paper, high-order compact difference method is used to solve the one-dimensional nonlinear advection diffusion reaction equation. The nonlinearity here is mainly reflected in the advection and reaction terms. Firstly, the diffusion term is discretized by using the fourth-order compact difference formula, the nonlinear advection term is approximated by using the fourth-order Padé formula of the first-order derivative, and the time derivative term is discretized by using the fourth-order backward differencing formula. An unconditionally stable five-step fourth-order fully implicit compact difference scheme is developed. This scheme has fourth-order accuracy in both time and space. Secondly, for the calculations of the start-up time steps, the time derivative term is discretized by the Crank-Nicolson method, and Richardson extrapolation formula is used to improve the accuracy in time direction from the second-order to the fourth-order. Thirdly, convergence and stability of the difference scheme in seminorm, and norms, existence and uniqueness of the numerical solutions are proved, respectively. Fourthly, the Thomas algorithm is used to solve the nonlinear algebraic equations at each time step, and a time advancement algorithm with linearized iteration strategy is established. Finally, the accuracy, stability and efficiency of the present approach are verified by some numerical experiments.
中文翻译:
非线性对流扩散反应方程的高阶紧致差分法数值解
本文采用高阶紧致差分法求解一维非线性对流扩散反应方程。这里的非线性主要反映在对流和反应项中。首先,使用四阶紧致差分公式将扩散项离散化,使用四阶Padé逼近非线性对流项一阶导数公式,时间导数项通过使用四阶后向差分公式离散化。提出了一种无条件稳定的五步四阶完全隐式紧致差分格式。该方案在时间和空间上均具有四阶精度。其次,对于启动时间步长的计算,采用Crank-Nicolson方法离散时间导数项,并采用Richardson外推公式来提高时间方向上从二阶到四阶的精度。第三,差分方案的收敛性和稳定性 半范式 和 分别证明了数值解的范数,存在性和唯一性。第四,采用托马斯算法求解每个时间步长的非线性代数方程,建立了具有线性化迭代策略的时间提前算法。最后,通过一些数值实验验证了该方法的准确性,稳定性和有效性。