摘要
众所周知,LBB条件排除了在不可压缩流动N-S方程空间离散中采用速度u和压力p同阶线性插值的简单单元。基于压力泊松(Poisson)方程的分步算法曾被认为可以绕开LBB条件限制,然而近年来研究表明,并非各种类型的分步算法都能有效地避开LBB条件。本文针对不同雷诺数下的平面Poiseuille流动问题模拟,分析对比了当采用不同类型的u-p单元空间插值时增量与非增量迭代分步算法的稳定性与精度,为合理选择分步算法和u-p插值类型提供了依据和参考。
It is well known that the LBB stability condition precludes the use of elements with the equal low order of interpolation for velocity u and pressure p in the numerical modeling of the incompressible N-S equations. The fractional step algorithm based on the pressure Poisson equation was reported and well recognized to be capable of circumventing the restrictions imposed by the LBB condition. However, the recent work of Guermond indicates that the incremental version of the fractional step algorithm can hardly circumvent the LBB condition with success, and the non-incremental version may work well with equal-order interpolations only if the time step size is chosen to be sufficiently larger than a critical one. In the present paper a numerical study on stability and accuracy of the non-incremental and the incremental versions of the iterative fractional step algorithm is carried out with the plane Poiseuille flow problem under different Reynolds numbers. The results and conclusions obtained by the present study provide some references and instructions in proper use of the fractional step algorithm with a right choice of the u-p interpolation approximations.
出处
《计算力学学报》
EI
CAS
CSCD
北大核心
2007年第3期275-279,共5页
Chinese Journal of Computational Mechanics
基金
国家自然科学基金(1027202710590354)资助项目
关键词
不可压缩N-S方程
H-P插值近似
分步算法
雷诺数
稳定性
精度
incompressible N-S equation
u-p interpolation approximations fractional step algorithm
Reynolds numbers
stability
accuracy
