Radiative transfer properties of a shocked Venus model atmosphere

Abstract

An analytical investigation of the equilibrium radiation of shocked 80% CO 2 , 20% N 2 was performed using the constant property flat slab model including non-gray self-absorption for typical Venus entry conditions. It was found that the important radiators are the fourth positive group of CO, the continuum from carbon, and the line emission from neutral carbon. The method was compared with available experimental data and good agreement was found. Most of the radiation was found to occur in the middle and far ultraviolet portions of the spectrum. The heat-transfer results are presented in a form which is useful for approximating radiation loads on a Venus entry vehicle. NomenclatureB\ = Planck function c = speed of light E t = radiance Ei = third exponential integral e = electron charge /» = oscillator strength h = Planck constant k = Boltzmann constant ra = electron mass NLi -number density of absorbing state q R = radiation flux 7*0 = classical electron radius RN = nose radius U m = freestream velocity VE = entry velocity j8 = ballistic coefficient T = radiation-cooling parameter 7# = entry angle 7i = half width A = slab thickness X = wavelength MX = absorption coefficient v = frequency p = density po = Earth standard density p m = freestream density o-\ -cross section for photon absorption Subscripts X = at a wavelength at a frequency = before shock