二维槽道湍流拟序结构的大涡模拟

LES OF THE COHERENT STRUCTURES IN TWO-DIMENSIONAL TURBULENT CHANNEL FLOW

本文采用大涡模拟的方法,对二维槽道湍流流动进行了数值模拟。采用Chorin的分步投影法求解大尺度涡运动的Navier-Stokes方程,小尺度涡采用三种亚格子（SGS）模式分别模拟,给出了不同亚格子涡粘性模式下的模拟结果。对固壁面采用了壁函数。模拟结果再现了二维槽道流动拟序结构的发展演变过程。通过对不同入口速度下的瞬态流场的比较,揭示了入口速度分布对流场的影响。

The two-dimensional turbulent channel flows are simulated through large-eddy simulation. The Navier-Stokes equations are solved with Chorin's fractional-step projection method, the small-scale motions are modeled by three different subgrid-scale (SGS) models respectively. The wall function is used in the near wall region. The simulation results give detailed information of vortexes evolution process. The numerical results also show that the inlet conditions have remarkable effect on the coherent structures in the channel flow. Computational results give the transition process that from laminar flow to turbulent flow.