Accession Number : AD0673877

Title :   APPLICATION OF MATCHED ASYMPTOTIC EXPANSIONS TO RADIATIVE TRANSFER IN AN OPTICALLY THICK GAS,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Emanuel,George

Report Date : JUN 1968

Pagination or Media Count : 53

Abstract : Radiative transport of thermal energy between concentric spheres is treated by the method of matched asymptotic expansions when the intervening grey gas is optically thick. Adjacent to each wall is a thin thermal layer in which the Rosseland diffusion approximation is invalid. A unique feature of this analysis is the direct application of matched asymptotic expansions to an integral equation. A close connection is thereby established between the structure of the wall layers and the Milne problem of astrophysics. Using the asymptotic approach, uniformly valid results are obtained for the emissive power, temperature slip at the walls, and heat flux. The asymptotic results are compared with the Rosseland approximation and with a numerical solution. A comparison is also made with the plane parallel layer problem to demonstrate the effect of a changed geometry. (Author)

Descriptors :   (*COUETTE FLOW, HEAT TRANSFER), SHELLS(STRUCTURAL FORMS), MATHEMATICAL MODELS, CORRELATION TECHNIQUES, WALLS, HEAT FLUX, THERMAL RADIATION, TRANSPORT PROPERTIES, OPTICAL PROPERTIES, THEORY, APPROXIMATION(MATHEMATICS), NUMERICAL METHODS AND PROCEDURES

Subject Categories : Statistics and Probability
      Fluid Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE