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Study of Emission Turbulence-Radiation Interaction in Hypersonic Boundary layers

L. Duan, M. P. Martín, I. Sohn, D. A. Levin, M. F. Modest

2011
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AIAA Journal
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Direct numerical simulations are conducted to study the effects of emission turbulence-radiation interaction in hypersonic turbulent boundary layers, representative of the Orion Crew Exploration Vehicle at peak-heating condition during reentry. A nondimensional governing parameter to measure the significance of emission turbulence-radiation interaction is proposed, and the direct numerical simulation fields with and without emission coupling are used to assess emission turbulence-radiation
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... action. Both the uncoupled and coupled results show that there is no sizable interaction between turbulence and emission at the hypersonic environment under investigation. An explanation of why the intensity of emission turbulence-radiation interaction in the hypersonic boundary layer is smaller than that in many combustion flows is provided. J=m 3 g = electronic state degeneracy H = shape factor, =, dimensionless h = specific enthalpy, J=kg h = Planck's constant h = enthalpy of formation, J=kg I = radiative intensity, W=cm 2 --sr J = diffusive mass flux, kg=m 2 s Le = Lewis number, dimensionless M = Mach number, dimensionless n = number density, m 3 p = pressure, P s s R=M s T, Pa q = heat flux, J=m 2 s q = turbulence kinetic energy, u 02 v 02 w 02 =2, m 2 =s 2 q C = conductive heat flux, @T=@x j , J=m 2 s q R = radiative heat flux, J=m 2 s Re 2 = Reynolds number, u = w , dimensionless Re = Reynolds number, u = , dimensionless Re = Reynolds number, w u = w , dimensionless S ij = strain rate tensor, 1 2 @u i =@x j @u j =@x i , s 1 T = translational temperature or temperature in general, K T e = electron temperature, K T r = rotational temperature, K T v = vibrational temperature, K u = velocity, m=s u = friction velocity, m=s = boundary-layer thickness, mm = displacement thickness, mm " = emission coefficient, W=cm 2 --sr " = total emission, W=cm 3 " = dissipation rate, m 2 =s 3 = momentum thickness, mm = absorption coefficient, cm 1 = mixture thermal conductivity, J=K m s = wavelength, Å = mixture viscosity, kg=m s = density, kg=m 3 ij = shear stress tensor, 2S ij 2 3 ij S kk , Pa Subscripts b = blackbody value L = lower state s = chemical species U = upper state = boundary-layer edge = at a given wavelength Superscripts = inner-wall units = normalized quantity

doi:10.2514/1.j050508
fatcat:efdmv4nj6ndq3pyn4rlsksnrfy