中低雷诺数流动直接数值模拟的算法比较

文章采用不同的算法对中低雷诺数方腔驱动流动进行了直接数值模拟,所用算法分别是人工压缩方法、SIMPLE算法以及PISO算法.三种算法均采用有限体积法基于交错网格技术离散N-S方程,时间项采用全隐格式离散,对流项采用QUICK格式离散,并将它们得到结果与Ghia发表的基准解进行了比对.文中分析了在同样的收敛条件下,不同算法之间的稳定性,收敛速率以及准确性的差异,发现PISO算法在较低雷诺数Re=400和Re=1000情况下最准确,而人工压缩算法在雷诺数为5000时最准确,在所有计算的不同Re数条件下,发现人工压缩法达到收敛所需时间都是最少的,这可以使它成为中低雷诺数下研究直接数值模拟最好的算法之一.

Comparison on Different Schemes of Direct Numerical Simulation for Low/medium Reynolds Flow

Direct numerical simulation (DNS) for low/medium Reynolds lid-driven cavity flow with different schemes are presented. The semi-implicit method for pressure-linked equations (SIMPLE), pressure-implicit splitting of operations (PISO) and pseudo-compressibility schemes are used. The N-S equations are all discretised by the Finite Volume Method for the three schemes, with the same staggered grid arrangement, the fully implicit time-stepping scheme and the QUICK scheme for the discretization of the temporal items and convective transport terms, the results are compared with the benchmark solution reported by Ghia1]. Under the same convergence criteria condition, difference in the stability, accuracy and convergence rate are analyzed. The PISO scheme is the most accurate scheme for low Reynolds number of Re=400 and 1000 flow. The pseudo-compressibility scheme is found to be the most accurate for Re=5000 flow. Besides, pseudo-compressibility scheme cost the minimum time to achieve convergence for all the cases, which shows it is one of the best choice for DNS of the low/medium flows.