High-Speed Magnetohydrodynamic Flow Control Analyses with Three-Dimensional Simulations

Abstract

Magnetohydrodynamic studies of high-speed flow control are described with emphasis on understanding fluid response to specific plasma-based perturbations. The theoretical model consists of a verified blend of first principles and empirical components. Detailed analysis is presented of the effect of magnitudes and gradients of magnetic and electric fields, their orientation relative to the velocity vector, ionized region location and extent, and various nondimensional parameters. The balance between ponderomotive force and heating is a major determinant of the effectiveness through competition between work and ohmic dissipation and viscous/inviscid interactions play a crucial role by distorting the velocity field. The interaction with an external circuit through electrodes is relatively efficient when fluid is slowed and energy is extracted, but yields high boundary-layer heating and loss of control performance when fluid is accelerated. These observations are employed to unify results focused on a broad range of objectives. Specific flowfields examined include heat transfer reduction in an Edney type-IV interaction at Mach 8, three-dimensional separation suppression at Mach 5 with magnetic-field-facilitated momentum transfer, inviscid instability-growth-rate modulation in an entropy layer at Mach 6, and energy management in simulated tip-to-tail scramjet designs of both axisymmetric and rectangular cross sections.