A LES-based Eulerian-Lagrangian approach to predict the dynamics of bubble plumes

摘要

An approach for Eulerian-Lagrangian large eddy simulation of bubble plume dynamics is presented and its performance evaluated. The main numerical novelties consist in defining the gas liquid coupling based on the bubble size to mesh resolution ratio (D-p/Delta(x),) and the interpolation between Eulerian and Lagrangian frameworks through the use of delta functions. The model's performance is thoroughly validated for a bubble plume in a cubic tank in initially quiescent water using experimental data obtained from high-resolution ADV and Ply measurements. The predicted time-averaged velocities and second-order statistics show good agreement with the measurements, including the reproduction of the anisotropic nature of the plume's turbulence. Further, the predicted Eulerian and LagTangian velocity fields, second-order turbulence statistics and interfacial gas-liquid forces are quantified and discussed as well as the visualization of the time-averaged primary and secondary flow structure in the tank. (C) 2015 The Authors. Published by Elsevier Ltd.