UNSTEADY, DIFFUSING, REACTING, TUBULAR FLOW WITH APPLICATION TO THE FLOW IN A GLOW DISCHARGE TUBE.

Abstract

A theory is given for the concentration profile of a diffusing, reacting, partially dissociated gas as it convects down a glow discharge tube. Initially, the atom concentration profile is a step function. The theory further requires incompressible two-dimensional or axisymmetric Poiseuille flow. Measurement of the profile at various positions along the tube can be used to deduce the atom-molecule diffusion coefficient. A first- and second-order solution for the atom concentration is given that accounts for axial diffusion and dispersion as well as gas-phase and wall recombination. By means of the first approximation, a quadratic equation is obtained that relates two dimensionless parameters. One of these contains only measured quantities, while the other contains the desired diffusion coefficient. Because of its quadratic form, each experiment results in two values for the diffusion coefficient. One value corresponds to axial diffusion dominating dispersion; the other corresponds to the reverse situation. A method is given for resolving this nonuniqueness. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1966
Accession Number
AD0480983

Entities

People

  • George Emanuel

Organizations

  • The Aerospace Corporation

Tags

DTIC Thesaurus Topics

  • Coefficients
  • Diffusion
  • Diffusion Coefficient
  • Discharge Tubes
  • Dispersions
  • Equations
  • Flow
  • Glow Discharges
  • Poiseuille Flow
  • Quadratic Equations
  • Step Functions
  • Two Dimensional

Fields of Study

  • Mathematics

Readers

  • Calculus or Mathematical Analysis
  • Fluid Mechanics and Fluid Dynamics.
  • Molecular Photonics/Laser Physics