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Author
Kung, H. C. | Cohen, I. M.
Title
Rayleigh Problem in a Compressible Gas With Small Radiative Heat Transfer.
Coporate
Brown Univ., Providence, RI
Sponsor
Office of Naval Research, Washington, DC
Contract
NR-562-35
Keywords
radiative heat transfer | equations | Reynolds number | flow field | boundary layers
Abstract
The flow of a viscous, compressible, heat conducting fluid near an impulsively started infinite flat plat is considered in the limiting case of a weakly radiating gray gas. The plate is thermally insulated. The time is restricted to be of the order of the ratio of photon mean free path to plate velocity, and the Reynolds number based on photon mean free path must be large compared with M6 (M is Mach number of the plate). Then the flow field is separated into two asymptotically significant regions: a viscous boundary layer and an inviscid outer region. the smallness of the radiation-convection ratio I enables us to compute the radiation-perturbed flow field as an interaction on the radiationless solution. For an optically thick gas (optically finite boundary layer), we find that the effect of thermal radiation is limited to the boundary layer. Radiative transport lowers the temperature of the fluid close to the plate and raises the temperature of the fluid away from the plate. for an optically finite gas (optically thin boundary layer), the temperature of the fluid very close to the plate is substantially lowered, the fluid in the rest of the boundary layer is heated by radiaiton, and there are waves propagating in the outer region due to the radiative heat flux from the boundary layer.