对CELS算法在多重网格下的数值试验

NUMERICAL EXPERIMENTS OF CELS ALGORITHM WITH MULTIGRID METHOD

求解不可压流体耦合方程的直接解法（CELS算法）在许多计算问题中体现了其优越性．多重网格法在加速数值计算的收敛速度方面也体现出了其有效性．本文把CELS算法在多重网格下实施，使用原始变量法，对圆管突扩通道和外掠后台阶的层流流动进行了计算，并与Armaly等人的实验数据进行了比较．结果表明，这种结合是很有效的．

CELS (Coupled Equation Line Solver) algorithm, which is based on the simultaneous solution for pressure and velocity along lines, successfully solved many flow problems. Multigrid technique can efficiently eliminate errors, and obtain a converged solution quickly. The present paper presents a simple, robust, and efficient method dealing with pressure-velocity coupling problems with primitive variables. The field equations are discretized by exponential scheme and pseudo-time step and solved by CELS using multigrid technique. Two test cases are the sudden-expansion pipe and the backward-facing step laminar flow. Good agreement is found with the experimental measurements of Armaly etc. and with the numerical results of Stella and Guj who used vorticity-velocity formulation.