任意拉格朗日-欧拉(ALE)法求解三维湍流流动

Three Dimensional Turbulent Flow Computation with Arbitrary Lagrangian-Eulerian method

本文推导了旋转叶轮内流湍流N-S方程计算的ALE格式。以网格的虚拟运动计算对流作用;采用粘性子循环时步、拉格朗日子循环时步加速收敛;改进上风格式为部分施主单元格式来减小扩散同时实现良好的计算性能;由通量限制控制耗散截断误差;计算中引入短波长阻尼以消除不规则性;以亚网格(SGS)湍流模式模拟湍流运动。

In this paper, Arbitrary Lagrangian-Eulerian computing schemes deduced for the computation of three dimensional turbulent flow within rotating impeller channel. The convection effect is simulated by the pseudo-moving of grids. Viscous sub-cycle time step and Lagrangian sub-cycle time step are adopted to accelerate convergence. The upwind scheme is improved into part-donated scheme to diminish diffusion. Flowrate restriction is used to control dissipitive truncation error. A short wave damp is introduced to reduce the computational corrugation. Large Eddy Simulation(LES) method, or say Sub-grid-Scale(SGS) turbulent model is adopted to simulate turbulent flow. Eckardt's experimental results on centrifugal impeller is used to examine the method and to illustrate its effectiveness.