特征无反射边界条件应用于二维圆柱绕流模拟

Characteristic Non-reflecting Boundary Conditions Applied in Two-dimensional Cylinder Flow Simulation

采用特征无反射边界条件和吸收层技术相结合的边界处理方法,研究了二维圆柱绕流模拟的边界反射问题。近年来在计算气动声学中提出了将大涡模拟和声学传播方程结合的混合方法求解声场,基于计算量的考虑,须在较小的计算区域内进行大涡模拟,这就需要在计算区域较小时,边界的反射尽可能小。作为大涡模拟研究的技术储备,将该方法应用于二维圆柱绕流的模拟中。数值结果表明这种方法在计算区域较小时,能起到很好的无反射效果,计算结果与前人在计算区域取得很大时的结果比较吻合。

The far field boundary reflecting problem of two-dimensional cylinder flow simulation was studied using the characteristic non-reflecting boundary conditions and damping layers methods.In recent years,in computational aeroacoustics area,the hybrid method of large eddy simulation and acoustic propagation equations was proposed to solve the sound field.Considering the amount of calculation,large eddy simulation should be carried out in a small region.This requires that the reflecting at the far field boundary should be as small as possible.As a preparation for large eddy simulation,the hybrid method is applied to the two-dimensional cylinder flow simulation.The numerical results show that the method can play a very good non-reflecting effect,and the calculation results agree with the previous numerical results obtained in the larger computational region.