Magnetic control of flow past a blunt body: Numerical validation and exploration

Computational and theoretical studies of a Mach 5 flow over a hemisphere were carried out to validate a new computer code for magnetogasdynamic simulation, and to examine the possibility of heat transfer mitigation through magnetic control. Sample calculations were made using a local solution developed by W. B. Bush [J. Aerosp. Sci. 25, 685 (1958); 28, 610 (1961)] for the stagnation point flow over an axisymmetric blunt body with an imposed dipole magnetic field. Numerical computations, which obviated many of the simplifications inherent in the Bush theory, were carried out employing the low magnetic Reynolds number approximation. Both models indicate that an imposed dipole field can slow the flow in the conductive shock layer and consequently reduce the wall heat flux in the vicinity of the stagnation point. The theoretical model predicts a slightly higher level of heat transfer than that obtained computationally, but there is good agreement between the two models in the fractional change in heat transfer with increasing strength of the applied magnetic field. For both models, nonuniform electrical conductivity was found to reduce the effectiveness of a given applied field. Magnetic flow control is seen to have a sound physical basis, and may prove to be a useful technology for heat transfer mitigation.