Numerical simulation of MHD on sudden expansion duct under strong transverse magnetic field

Abstract

This research delves into the analysis of quasi-two-dimensional flow dynamics in liquid metal confined within a sudden expansion duct, subjected to a strong magnetic field. Utilizing numerical simulations derived from the SM82 model, the study concentrates on examining the magnetohydrodynamic (MHD) responses across a defined range of parameters. These simulations were conducted maintaining a constant Reynolds number (Re), while systematically varying the Hartmann number (Ha) across a spectrum of values [1000, 2000, 5000, 10000, 15000, 20000] to enable a thorough exploration of the magnetic fields influence on the flow dynamics. The outcomes of this study reveal a marked transition in flow behavior corresponding with the escalation in magnetic field strength. Notably, as the magnetic field intensifies, the flow undergoes a transformation from a state of instability to stability. This shift is predominantly characterized by a diminution, followed by a complete cessation, of shear vortex shedding. Additionally, beyond a Ha of 5000 and at a longitudinal position of x = 6, both the velocity and pressure profiles begin to exhibit near-identical and symmetric characteristics. Post the Ha exceeding 1000, the vortex profile demonstrates symmetry about the y=0 axis. These observations significantly enhance the comprehension of MHD fluid dynamics under quasi-two-dimensional conditions.