Asymptotic Theory of an Optically Thick Radiating Gas Flow Past a Smooth Boundary at Moderate Radiation Strength

抄録

Asymptotic behaviours of a grey, inviscid, non-conducting gas flow past a black body with arbitrary smooth shape are studied analytically. It is shown that the flow field is composed of three parts; an isentropic outer region, a diffusion type (Rosseland type) middle layer and a purely radiative inner layer. These two layers are thin, in which boundary layer treatments are made. Formal solutions in the inner layer and reduced equations with reduced boundary conditions (e.g. slip coefficients) in the other regions are obtained to the first orders of expansion with respect to the inverse square root of a large global optical thickness.
The results are compared with those by the moment method (P. Cheng; AIAA J. 4 (1966) 238) and its modification. The moment method does not give the inner layer. It gives smaller temperature slip coefficients. Its curvature effects on the middle layer are different from those by the present exact treatment.