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Microwave energy deposition is a novel method for flow control in high-speed flows. Experiments have demonstrated its capability for beneficial flowfield modification in supersonic flow including, for example, drag reduction for blunt bodies. A fully three-dimensional, time-accurate gas dynamic code has been developed for simulating microwave energy deposition in air and the interaction of the microwave-generated plasma with the supersonic flow past a blunt body. The thermochemistry model includes 23 species and 238 reactions. The code is applied to the simulation of microwave energy deposition in supersonic flow past a hemisphere cylinder. The computed centerline surface pressure is compared with the experiment. The interaction of the microwave-generated plasma with the flowfield structure is examined. Nomenclature c p i = specific heat at constant pressure for species i D = diameter of cylinder E, E o = electric field, maximum electric field H = total enthalpy per unit mass of mixture h o f i = heat of formation of species i at temperature T ref h i = static enthalpy of species i per unit mass of species i h = static enthalpy per unit mass of mixture K k = reaction coefficient for reaction k k = Boltzmann constant, 1:38 10 23 J=K k E = microwave wave number, 2= M = representative mass for ions and neutrals M i = molecular weight of species i, kg=kg mol M i = species i (e.g., M 1 e) M 1 = Mach number m = number of reactions m e = mass of electron N = total concentration of species excluding electrons, cm 3 N e , N crit e = electron concentration, critical electron concentration, cm 3 N i = concentration of species i, cm 3 n = number of species including electrons p = static pressure _ p i k = rate of production of species i from reaction k Fig. 1 Interaction of microwave-generated plasma with cylinder. Fig. 2 Centerline pressure vs time. _ q = rate of heating of gas per unit volume R = universal gas constant, 8314 J=kg mol K T = static (translational) temperature of mixture T e = electron temperature u i = mass-averaged velocity component in i direction V dr = drift velocity x i = Cartesian coordinate Y i = mass fraction of species i, Y i i = i = fraction of h i converted into heating of gas h i = rate of change in enthalpy due to reaction i = 2m e =M " = total energy per unit mass of mixture = wavelength of microwave = rotational relaxation factor, dimensionless e = effective frequency of electron collisions 0 ik , 00 ik

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