180°方形弯管中湍流流动的大涡模拟

Large eddy simulation of turbulent flow in a square duct with 180° bend

把大涡模拟应用于复杂几何形状的流域是一个重要研究课题。对１８０°方形弯管中的湍流流动作大涡模拟，以网格节点为中心的交错网格作为离散网格，用有限体积方法和中心差分进行空间离散，用Ａｄａｍｓ－Ｂａｓｈｆｏｒｔｈ格式进行时间离散，用简单的Ｓｍａｇｏｒｉｎｓｋｙ模型来作为次网格湍流模型。用多重网格方法求解压力方程以提高计算效率。数值模拟结果与实验结果取得了很好的一致。

Application of large eddy simulation (LES) to complex geometry is an important research subject in LES. The turbulent flow in a square duct with 180° bend was simulated. Discretization of the partial differential equations in space used the finite volume approach and central differencing on a vertex centered grid, and discretization in time employs the Adams Bashforth scheme. The subgrid scale modeling used the Smagorinksy model. The pressure equation was solved by using multigrid method to achieve high computational efficiency. The results from numerical simulation are in good agreement with the experimental data.