Numerical model for bubble breakup and coalescence in turbulent gas liquid dispersion

Abstract

In recent years, much work has been done on bubble breakage, coalescence, and bubble size distributions in gas-liquid dispersions. Few of them however, considered both breakage and coalescence phenomena simultaneously in estimating bubble size distribution. In present study an attempt is made to develop a model that considers both breakage and coalescence based on existing frame works and recent advances described in the literature. Two-step mechanisms are considered for both the breakage and coalescence models. The bubble breakage is structured as the product of the bubble-eddy collision frequency and breakage efficiency in gas-liquid dispersions. The coalescence function considers the product of bubble-bubble collision frequency and coalescence efficiency. The model overcomes several limitations observed in previous efforts such as determination of parameters through experiment, narrow range of operating conditions, and narrow range of geometries. Favorable agreement is found between the predictions of the model and the experimental data obtained for the 'average bubble size and bubble size distribution. The percentage of error was estimated and found within"' 17%. The model is also extended to examine the influence of physical properties on bubble size distribution.