Some problems of second order modelling of mass transfer in a turbulent gas mixture
Abstract
Some of the problems encountered in the investigation of density effects in a turbulent flow are studied theoretically and experimentally, with attention focused exclusively on the mixing of two nonreactive gases in a free subsonic round jet. The theoretical part involves the second-order modeling of such a flow with the use of mass-weighted averages; a model with eight transport equations is proposed. The experimental part consists in the measurement of mean velocity and concentration, and four significant Reynolds stresses in 21 sections of a CO2-air jet issuing from a long pipe at Reynolds number of 54,100. A direct comparison between numerical predictions and experimental data makes it possible to assess a model based on rather crude extensions of schemes previously developed for buoyant flows. In addition, difficulties of turbulence modeling for a variable density flow are evaluated in an attempt to identify the critical aspects that require improvement.
- Publication:
-
Structure of turbulence in heat and mass transfer
- Pub Date:
- 1982
- Bibcode:
- 1982sthm.book..509C
- Keywords:
-
- Computational Fluid Dynamics;
- Free Jets;
- Gas Mixtures;
- Mass Transfer;
- Turbulent Flow;
- Air Jets;
- Gas Density;
- Mathematical Models;
- Turbulent Jets;
- Velocity Distribution;
- Fluid Mechanics and Heat Transfer