Effect of induced magnetic field on magnetohydrodynamic control for high-velocity atmospheric entry

The effect of the induced magnetic field on the magnetohydrodynamics (MHD) control for high-velocity atmospheric entry is evaluated in this work. For this purpose, numerical simulations of hypersonic MHD flow over a blunt body are carried out in laminar and turbulent flows, respectively. The turbulent flow is simulated based on Reynolds-averaged Navier–Stokes equations with the Spalart–Allmaras model. The thermodynamic properties and composition of weakly ionized air are calculated in thermochemical equilibrium at a lower altitude. The results show that the induced magnetic field generally weakens the effectiveness of the applied magnetic field, including the increase in shock standoff distance and mitigation of heat flux. Besides, the weakening effect of the induced magnetic field significantly increases with the increase in the Mach number. For a higher-velocity entry vehicle, the magnetic Reynolds number can be large, and the induced magnetic field should be considered in numerical simulations. Moreover, the impact of induced magnetic field on the heat flux mitigation in turbulent flow is greater than that in laminar flow. These studies provide a comprehensive analysis of the effect of induced magnetic field and the validity of low-magnetic-Reynolds-number (low-Rem) approximation during hypersonic MHD control.