Characterization of Applied Magnetohydrodynamic Effects on Hypersonic Reentry Flows

The effect of magnetohydrodynamic (MHD) interactions on the postshock naturally generated plasma is investigated in hypersonic flows with Mach numbers of 24, 20, and 16. High-fidelity continuum laminar simulations coupled with Lorentz force and Joule heating effects are carried out over an axisymmetric blunt-nosed body with an external magnetic field of about 1T. The shock and boundary-layer profiles are significantly altered with MHD interactions. If the body is sufficiently streamlined with a rounded nose to ensure plasma generation, modification of viscous interactions at the surface represents a promising method of drag and thermal load reduction at high Mach numbers. It is observed that MHD interactions are strong enough to induce flow separation for the case with the highest Mach number and lower Knudsen number. MHD interactions reduce thermochemical nonequilibrium in high-Knudsen-number cases, while simultaneously enhancing the concentration of ionic species around blunt bodies due to the increased flow residence time. The application of an external magnetic field decreases heat transfer and shear stresses near the leading edge by approximately 50%, thereby reducing the overall thermal and mechanical loads on the vehicle. The changes in ionized and neutral species concentration with the presence of magnetic fields are closely reported for three points along the reentry trajectory. The shock standoff distances are examined and compared with the existing data in the literature, showing very good agreement with the measurements, particularly for high-Knudsen-number flows.