Accession Number : AD0675995

Title :   FREE MOLECULAR FLOW THROUGH A CIRCULAR TUBE OF FINITE LENGTH,

Corporate Author : AEROSPACE RESEARCH LABS WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Nagaraja,Kanakanahalli S.

Report Date : JUN 1968

Pagination or Media Count : 52

Abstract : The free-molecular flow rates through untapered circular tubes of finite lengths are determined for several length to radius ratios (L/R). The governing equations, which are derived on the assumptions that the reflection from the wall is diffuse and the arrival rates of molecules at an elemental area follow the 'cosine law' distribution, are evaluated numerically. The Clausing integral equation, which determines the flux of molecules at an element of the interior wall of the tube, is solved on an IBM 7094 by an iterative scheme. An analysis of the Clausing integral equation provides very useful information on the behavior of its solution, and this, together with the mass conservation principle for checking the numerical results, particularly for higher values of L/R. Knowing the distribution of the flux of molecules along the interior wall of the tube, the flux of molecules arriving from the wall at both exit and entrance planes are computed by straightforward numerical integration. The total flux rates through the exit plane are shown to agree with those obtained by DeMarcus by a variational technique for certain values of L/R. (Author)

Descriptors :   (*RAREFIED GAS DYNAMICS, PIPES), RINGS, EQUATIONS OF MOTION, KINETIC THEORY, ITERATIONS, MOLECULAR PROPERTIES

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE