一种新的定压边界处理方法

A new numerical treatment of specified pressure boundary conditions

依据SIMPLE算法中边界压力的外推格式,结合定压边界条件重新推导了邻近边界内节点的压力计算公式.根据NEUMANN特性给出了新的定压边界速度计算公式,用IDEAL算法来处理压力和速度的耦合.讨论了定压边界流动传热问题的求解步骤.通过几个经典算例将本方法与文献方法进行了对比,结果表明本方法提高了定压边界问题数值解的精度,加快了迭代过程的收敛.

According to the extrapolation scheme of boundary pressure in SIMPLE algorithm,the pressure formula of internal node near the boundary is derived with specified pressure boundary.Based on the feature of Neumann boundary for velocity,a new computational formula of boundary velocity is derived.The coupling of velocity and pressure is treated by using the IDEAL algorithm,and the steps in solving the fluid flow and heat transfer problem with specified pressure boundary are illustrated.The new method is compared with the methods used in the literature in solving several typical problems.Results show that the proposed method obviously enhances the accuracy of numerical solution and accelerates the convergence of iteration process.