Drag and pressure fields for the MHD flow around a circular cylinder at intermediate Reynolds numbers

[摘要] Steady incompressible flow around a circular cylinder in anexternal magnetic field that is aligned with fluid flow directionis studied forRe(Reynolds number) up to 40 and theinteraction parameter in the range0≤N≤15(or0≤M≤30), whereMis the Hartmann number related toNby therelationM=2NRe, using finite difference method.The pressure-Poisson equation is solved to find pressure fields inthe flow region. The multigrid method with defect correctiontechnique is used to achieve the second-order accurate solution ofcomplete nonlinear Navier-Stokes equations. It is found that theboundary layer separation at rear stagnation point forRe=10is suppressed completely whenN<1and it started growing againwhenN≥9. ForRe=20and 40, the suppression is notcomplete and in addition to that the rear separation bubblestarted increasing whenN≥3. The drag coefficient decreasesfor low values ofN(<0.1)and then increases with increaseofN. The pressure drag coefficient, total drag coefficient, andpressure at rear stagnation point vary withN. It is also found that the upstream and downstream pressures on the surface ofthe cylinder increase for low values ofN(<0.1)and rear pressure inversion occurs with further increase ofN. These results are in agreement with experimental findings.

[学科分类] 应用数学