Investigation of Plasma Exhaust Profile Manipulation Using Magnetic Fields

In this research, the magnetoplasmadynamic (MPD) effects of applying a toroidal magnetic field around an ionized exhaust plume were investigated to manipulate the exhaust profile of the plasma jet under near vacuum conditions. Tests for this experiment were conducted using the West Virginia University (WVU) Hypersonic Arc Jet Wind Tunnel. A series of twelve N52 grade neodymium magnets were placed in different orientations around a steel toroid mounted around the arc jet’s exhaust plume. Four different magnet orientations were tested in this experiment. Two additional configurations were run as control tests without any imposed magnetic fields surrounding the plume. Each test was documented using a set of 12 photographs taken from a fixed position with respect to the flow. The photographic data was analyzed by comparing images of the exhaust plume taken 10, 20, and 30 seconds after the plasma jet was activated. Analysis of the collected images revealed that configurations where the magnetic field lines were tangential to the toroid’s central axis had very little influence on the size of the exhaust profile across all time steps. In contrast, the configurations where magnetic field lines ran parallel to the toroid’s central axis expanded the exhaust profile across all time steps. Statistical analysis was performed to demonstrate significant influence of jet duration and magnetic field orientation on the cross sectional area of the plume and also showed insignificant duration-magnetic field interaction effects on the plume behavior.