Experimental and Computational Studies of Low-Temperature M=4 Flow Deceleration by Lorentz Force

Abstract

The paper presents results of cold MHD flow deceleration experiments using repetitively pulsed, short pulse duration, high voltage discharge to produce ionization in a M=4 nitrogen flow in the presence of transverse DC electric field and transverse magnetic field. Effective flow conductivity is significantly higher than was previously achieved, σeff=0.1 S/m. MHD effect on the flow is detected from the flow static pressure measurements. Retarding Lorentz force applied to the flow produces a static pressure increase of 19%, while accelerating force of the same magnitude applied to the same flow results in static pressure increase of 11%. The effect is produced for two possible combinations of the magnetic field and transverse current directions producing the same Lorentz force direction (both for accelerating and retarding force). The results of static pressure measurements are compared with predictions of a 3-D Navier-Stokes / MHD flow code. The static pressure rise predicted by the code, 18% for the retarding force and 8% for the accelerating force, agrees well with the experimental measurements. Analysis of the