Hypersonic Vehicle MHD Power Extraction Concept Utilizing Mach Stem Thermal Ionization
We present an initial analysis of on a new MHD power extraction device for reentry vehicles that provides significant energy extraction at speeds of Mach 10 and below. Lower Mach number operation is accomplished by creating a strong normal shock inside a duct which heats alkali seed material to ionization temperatures. The design consists of a convergent inlet followed by an interior channel. The compression ramp angle is chosen such that a normal shock, or Mach stem, is formed near the throat. Inside the duct a Faraday generator extracts energy through aerodynamic electrode fins. The Navier-Stokes equations were solved for this geometric configuration in combination with a one dimensional MHD generator model for operation at 20km, 30km and 40km altitude and Mach 8 or 10. Results indicate that over 1MW/m may be generated with a nominal 50cm high inlet at Mach 10. 2011 by Princeton University.