Numerical Analysis of Turbulence Structures Induced by Bubble Buoyancy

Abstract

The turbulence structure in a rising bubbly flow driven by bubble buoyancy has been analyzed using the Eulerian-Lagrangian model. A new method of calculating the two-way interaction between the dispersed bubbles and the liquid phase was proposed to accurately simulate the local fluctuations of liquid flow induced by bubble migration. The present two-dimensional simulation revealed that, (1) in the case of the larger bubble, the turbulence structure has the longer wavelength in the vertical direction, and, (2) the wave spectrum of kinetic energy of the liquid phase is sensitive to the average void fraction and the lift force of the bubbles.