Simulating large-scale bubble plumes using various closure and two-phase turbulence models

Large-scale, bubbly plumes have been simulated by a commercial CFD code using various models and correlations for the interfacial forces between the phases and for bubble-induced turbulence. Steady-state simulation results are compared with time-average plume behaviour obtained from a novel experimental series on large-scale bubble plumes. Numerical effects like e.g. numerical scheme and grid dependence are examined and the important issue of plume fluctuations is addressed. It is shown that it is necessary to include an appropriate model for the lateral interfacial forces like lift and turbulent dispersion to obtain the correct spreading of the plume observed experimentally. Including those and using standard drag coefficient, the agreement with the experiments is reasonable. The different two-phase turbulence models are either inappropriate or have very little influence on the simulation results, which do not predict the gas velocity everywhere in the plume correctly.