Modulation of the recirculation region due to magneto hydrodynamic flow

Abstract

Turbulent flow characteristics on the fully submerged square rib are dominated by large scale flow structures. Flow separation, recirculation and reattachment region at the wake region of rib composes the vortex shading which may generate unwanted vibrations. The present numerical simulation focused on the modulation of recirculation zone for the flow of Reynolds number (Re = 60,000) with different Hartmann numbers (Ha = 5, 25 and 50). The consequences of this study depict that the strength of the magnetic field in an average reduction of mean axial velocity in compared to the flow without magnetic field. Moreover, the induced magnetic field is capable of reducing the recirculation zone at the wake region of the square rib. The frontal recirculation area is rather amplified due to the induced magnetic field compared to the flow without magnetic field. Turbulence strength is reduced for higher Hartmann number. In addition, turbulent kinetic energy (TKE), dissipation and vorticity are analyzed to understand the turbulent flow field and its modulation around the square rib due to different Hartmann numbers. The TKE, vorticity and dissipation are maximized near the bottom wall at the wake region of the rib.