确定SIMPLE算法中压力松弛因子的自适应方法

摘要

压力松弛因子的选取是SIMPLE(Swrni-Implicit Method for Pressure-Linked Equations,SIMPLE)算法在数值求解流体流动及对流换热问题的难点之一.针对非稳态流动问题,提出了一种SIMPLE算法中压力松弛因子的自适应方法,有效地避免了松弛因子对计算结果的影响.通过对两个算例,即二维方腔顶盖驱动流和突扩管道内的流动,并与压力松弛因子取定值时进行了比较,说明此算法可以在不需要对压力松弛因子进行猜测取值的情况下得到收敛解,且达到收敛解所需的CPU时间较短.%When the SIMPLE algorithm is used to solve the problem of fluid flow and heat convection numerically , one of the difficulties is how to choose the pressure relaxation factor. For the nonsteady flowing problem,this paper presents a method, which is the adaptive approach of stress relaxation factor of SIMPLE algorithm. It can effectively avoid the influence of the relaxation factor on the computed result. Two numerical examples,namely 2D lid-driven square cavity flow and sudden expansion pipe flow,are given and compared with that of fixed stress-relaxation factor. The algorithm can get the convergent solution without guessing the pressure relaxation factor. In addition,its CPU time consumed is usually less than that of traditional methods.