Accession Number : AD0274781

Title :   DIFFUSION IN EXPANDING ELECTRICALLY NEUTRAL GASES WITH LARGE PRESSURE GRADIENTS. PART I. DEVELOPMENT OF MATHEMATICAL MODEL

Descriptive Note : Memo rept.

Corporate Author : FRANKFORD ARSENAL PHILADELPHIA PA

Personal Author(s) : KATSANIS,D.J.

Report Date : OCT 1961

Pagination or Media Count : 30

Abstract : A study was conducted to deter ine the mathematical form of the theory for unsteady diffusion processes in ter s of specifically related physical concepts, mainly those of mechanics and thermodynamics. A mathematical model was developed for unsteady rapid expansion of a nonreacting binary inviscid mixture of perfect gases in which diffusion occurs. The analysis is based on Prigogine's method, which utilizes the concept of generalize flow. The derived equations depend on influence coefficients which can be related to a diffusion coefficient. Since the derivation is limited to macroscopic concepts, any diffusion which results in a macroscopically measurable change in gas mixture composition is admissible, whether it be molecular or turbulent. The final form of the model is similar to those of Prigogine, Chapman and Cowling, or DeGroot. However, the diffusion coefficient as discussed is slightly different and chemical reactions are excluded. (Author)

Descriptors :   *FLUID MECHANICS, *IRREVERSIBLE PROCESSES, *KINETIC THEORY, *MATHEMATICAL ANALYSIS, *THERMODYNAMICS, DIFFUSION, ENTROPY, GAS FLOW, GASES, PARTIAL DIFFERENTIAL EQUATIONS, PHYSICAL CHEMISTRY, PRESSURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE