可逆转轮单通道流动大涡模拟

Large eddy simulation of turbulent flows passage of reversible runner

为准确预测不可压复杂边界的湍流流动,本文应用高精度有限体积法对曲面边界湍流进行了大涡模拟。空间离散采用有限体四阶紧致格式,时间推进采用四阶Runge-Kutta法,压力-速度耦合应用四阶紧致格式的动量插值,亚格子应力模式采用动态Smagorinsky模式,复杂边界的处理则应用了浸没边界法,成功地实现了弯槽湍流、NACA0012标准翼型绕流流动和可逆式水泵水轮机转轮内单流道流动的大涡模拟计算,所得结果与已有结果或实验结果吻合良好,表明该方法对于湍流大涡模拟方法在流体机械工程领域中的应用和发展具有重要意义。

A high accurate finite volume method of non-uniform meshes for large eddy simulation （LES） is presented in order to precisely predict complex incompressible turbulent flows. The filtered Navier-Stokes equation is solved numerically on non-staggered grids with a finite volume fourth-order-accurate compact scheme for spatial discretization and fourth-order Runge-Kutta integration for time advancement. The pressure-velocity coupling is handled by the momentum interpolation method with a fourth-order-accurate compact scheme. The numerical simulations of a curved channel flow, a flow around a wing of NACA0012 section and a flow passage of a reversible pump-turbine runner are performed successfully by LES with a dynamic Smagroinsky model for subgrid stress and with immersed boundary method for nonslip boundray condition. The results are in good agreement with data in literatures. It is concluded that the proposed method has significant interests in application of LES in fluid machinery engineering.