湍流槽道流并行直接求解方法

Parallel direct method for turbulent channel flow

摘要:

采用并行直接求解方法（PDM-DNS）进行湍流槽道流的DNS模拟. 该方法能够实现较高效并行的DNS直接求解,在“天河二号”超级计算机上应用256核计算达到95%以上的并行效率. 4个算例的计算雷诺数分别为Re_τ=176、544、960、2000,并与相关的计算结果进行对比,验证了数值结果的可靠性. 利用速度压力法壁面边界条件易于处理的优点,结合浸没边界法技术,在雷诺数Re_τ=176的槽道中加入了局部毛刺带,为解决复杂边界条件的槽道流的问题提供了新的方法.

Abstract:

In this study, the direct numerical simulations of turbulent channel flow combined with Parallel Direct Method of DNS (PDM-DNS) are performed, and high parallel efficiency is obtained. A parallel efficiency of over 95% can be achieved on 256 cores of the Tianhe-2 supercomputer. Statistics of four cases with Re_τ=6,4, 960 and 2000 have been compared with the Lee&Moser’s results and the reliability is verified. Further, based on the advantage of finite-difference with immersed boundary condition easy to deal with wall boundary condition, a simulation added local burr band at Re_τ=176 has been performed to realize research of complex boundary condition. The proposed method provides a new tool for the study of turbulent channel flow with complex boundary condition.