通道中并列旋转圆柱的LB-DF/FD模拟

Simulation of flow around two rotating cylinders in a side-by-side arrangement at long channel using LB-DF/FD method

通过结合格子Boltzmann方法(LBM)和DF(Direct Forcing)/FD(Fictitious Domain)思想,建立了一种新的LB-DF/FD方法。采用两套网格系统,欧拉网格用于流体,拉格朗日网格用于固体,有效地避免了计算中重新生成网格的步骤,同时在处理流固问题方面优于LBM方法。通过模拟通道中单圆柱旋转的流场,验证了该方法的正确性;并利用该方法模拟了低雷诺数下通道中并列旋转圆柱周围的流场,分析了圆柱距离壁面间距gw和雷诺数Re对流场结构的影响。研究结果表明:gw显著影响了流场的结构及圆柱的受力;而Re对圆柱升力及Stokes单元数目的影响较大。

A new LB-DF/FD method,which combines the lattice Boltzmann method(LBM) and direct-forcing /fictitious domain(DF/FD) scheme,is established for fluid-solid interaction problem.The LB-DF/FD combines the good features of the LBM and the DF/FD method by using two unrelated meshes,an Eulerian mesh for the flow domain and a Lagrangian mesh for the solid domain,which avoids the re-meshing procedure.The present method is validated by simulations of the flow around a single cylinder in the channel.Flow around two circular cylinders in a side-by-side arrangement at low Reynolds numbers is numerically simulated.Effects of the spacing gap between the cylinder and wall gw and Renolds number Re are investigated.It's shown that gw remarkably affects lift and drag force and torque exerted on.cylinder,moreover,both the Stokes cell number and the lift force exerted on the cylinder depend heavily on the Re.