Numerical Study of Magnetohydrodynamic Flows past a Wedge Structure

Abstract

The laminar viscous and incompressible flow of an electrically conducting fluid across an unconfined wedge structure in the presence of transverse magnetic field has been studied. The wedge structure is an equilateral triangular cylinder. Two-dimensional numerical simulations have been performed for Reynolds number (Re) = 1 - 150 and Hartmann number (Ha) = 0 - 10 for a fixed confinement ratio of 1/30. The fluid is assumed to have uniform physical properties. The magnetic Reynolds number is very small such that the induced magnetic field is negligible compared to the applied magnetic field. The magnetic induction method in magneto-hydrodynamics (MHD) module built in ANSYS FLUENT solver has been employed to compute the flow fields. Results show that the complete elimination of vortex shedding is achievable if the applied magnetic field is strong enough. In the steady flow regime, it has been found that the recirculation length reduces with the increase in Ha. A minimal reduction in the drag coefficient is observed with the increase in Ha as long as unsteady flow is maintained (Ha < 7.3). However, the drag coefficient has a tendency to significantly increase with the increase in Ha in a steady flow. Similarly, the lift amplitude decreases with the increase in Ha indicating a diminishing effect on the strength of vortices. A critical Hartmann number (Hacr) of 7.3 has been found for Re = 100 at which complete suppression of vortex shedding is observed.