Numerical studies on the dynamics of bubble, turbulent, free shear flows: Effect of the interphase coupling on the global flow evolution
Abstract
We use direct numerical simulations to analyze the evolution of a temporally growing twodimensional free shear layer seeded with a dilute suspension of bubbles under gravity. The bubble concentrations are dilute enough so that bubble bubble interactions are negligible, but cumulative effects of bubbles alter the flow field. The evolution of the bubbles can then be determined by tracking many individual bubbles, and the flow field is advanced using the NavierStokes equations with a coupling term in the momentum equation representing the effect of the bubbles on the flow. We interpret the results in terms of the difference in the vorticity, bubble concentration, and pressure fields relative to the passive or one way coupled case. Due to the nature of the vorticity production mechanism, the net circulation is not affected by the bubbles, but local variations do occur, especially near the vortex center. In addition to the effect of the bubbles on the flow, the bubble field is also altered as a result of the twoway coupling. The location of bubble accumulation is shifted away from the vortex center and the magnitude of this accumulation is reduced relative to the passive case.
 Publication:

California Univ., Los Angeles Report
 Pub Date:
 December 1993
 Bibcode:
 1993ucla.reptS....M
 Keywords:

 Bubbles;
 Flow Distribution;
 NavierStokes Equation;
 Pressure Distribution;
 Shear Flow;
 Shear Layers;
 Turbulent Flow;
 Vortices;
 Momentum;
 Vorticity;
 Fluid Mechanics and Heat Transfer