气固两相圆柱绕流转捩两种模式的三维直接数值模拟

该文对随空间发展模式的三维气固两相圆柱绕流中颗粒与流体的单相耦合作用进行了直接数值模拟。气相流场采用高精度紧致差分方法的数值方法对N-S方程组进行直接求解,计算颗粒场时,选取Stokes数等于0．01、1、10的颗粒,采用Lagarangian方法跟踪其运动。颗粒与壁面采用了弹性碰撞的方法来模拟。重点考察了颗粒相受两种模式下拟序结构的作用,分析了不同Stokes数的颗粒扩散受其相应流场特性的影响。数值结果表明,颗粒扩散受两种模式的影响很大。在相同的Stokes数下,B模式下的颗粒场纵向和横向扩散要高于受A模式影响的颗粒场；而在相同雷诺数下,Stokes数越大,横向扩散越小,纵向扩散越大。

Three-dimensional Direct Numerical Simulation of Circular Cylinder Wake Transition in Gas Particle Flow

Direct numerical simulation is employed to investigate circular cylinder wake transition in gas particle flow. High accuracy compact finite difference method is used to solved the N-S equations directly.Lagrangian approach is employed to trace particles with different Stokes number (0.01,1,10).Particle-wall collision is simulated by elastic collision model.Influence of two modes of coherent structures to particle phase is importantly researched.And impact of different Stokes number is analyzed.The simulated results show that the particle dispersion patterns are still strongly dependent on the two different vortex modes.Under the same Stokes number,the dispersion ratio of transverse direction and spanwise direction in mode B is higher than that of mode A. While under the same Reynolds number,the larger Stokes number is,the less dispersion ratio of transverse direction is and the more of spanwise direction.