将已经建立的求解三维定常对流扩散方程的高阶紧致差分格式直接推广到三维非定常对流扩散方程的数值求解,时间导数项利用二阶向后欧拉差分公式,所得到的高阶隐式紧致差分格式时间为二阶精度,空间为四阶精度,并且是无条件稳定的。数值实验结果验证了本文方法的精确性和稳健性。
Based on our previous fourth-order compact difference scheme for the 3-D steady convection diffusion equation, a high-order compact implicit difference scheme for the 3-D unsteady convection diffusion equation is directly obtained. It is unconditionally stable and the local truncation error is second order for time and fourth order for space. Supporting numerical experiments are included to illustrate the high accuracy and robustness of present method.