Numerical Study of a MHD-Heat Shield

Abstract

Newly developed computational tools are used to compute hypersonic flow around a hemisphere-cylinder which utilizes a magnet located within the body. The magnetic force generated opposes the incoming flow thereby increasing the shock standoff distance and providing heat mitigation to the stagnation region. Several surface temperature scenarios are explored, though none result in significant change to the shock standoff distance. The Hall effect and ion slip phenomena are added to the plasma model through the electrical conductivity tensor and are validated by simulating channel flow between infinitely repeating electrodes with an applied magnetic field. The Hall effect stretches the current in the streamwise direction while ion slip reduces the stretching for the channel flow scenario. In the hemisphere-cylinder scenario, the strong Hall effect significantly lessens the effectiveness of the magnet at increasing the shock standoff distance while Joule heating reduces the effectiveness of heat mitigation observed in the stagnation region.

Magnetohydrodynamic Simulations of Hypersonic Flow over a Cylinder Using Axial‐ and Transverse‐Oriented Magnetic Dipoles

“…As mentioned in the beginning of this paper, there have been quite a few studies in this area over the last decade, and many of them demonstrated similar effects as the ones observed here. Particularly relevant to the current study is the work by Bisek et al [ 23 ], who carried out a computational investigation of near-hypersonic flow of argon gas over a hemispherical body with a dipole magnetic field and noticed similar effects on shock-standoff distance. Utilizing several electrical conductivity models, they achieved up to approximately 16% increase in shock-standoff distance with B max⁡ = 0.28 T. Numerical and experimental work by Bityurin and coworkers [ 17 , 35 , 36 ] on flow over a cylinder also showed an increase in shock distance (up to a 45% increase with B max⁡ = 0.45 T), as well as a decrease in temperature around the cylinder with the application of a magnetic field.…”

“…However, the dipole is essentially treated as a 2 D model completely independent of the z -direction coordinates. The ideal dipole field employed in this study is given by [ 23 ] …”

“…More recently, Grigoriadis et al [ 22 ] computed hypersonic MHD flow past a cylinder using the immersed boundary method. Bisek et al [ 23 ] investigated the effects of a magnetic field on hypersonic flow using variable electrical conductivity models and an argon gas medium in considering its application as a heat shield for reentry vehicles. Over the last few years, development of hypersonic MHD applications has begun to cluster into flow control, hypersonic inlets, and power generation [ 24 – 26 ].…”