Les for Bubble Plumes: Impact of the Interpolation Technique and the Size of the Bubbles on the Entrained Liquid Velocity

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Bruño Fraga, Thorsten Stoesser

Thursday 2 july 2015

14:05 - 14:25h at Europe 1 (level 0)

Themes: (T) Special session, (ST) Oil spill modelling

Parallel session: 12J. Special session: Oli Spill Modelling

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A Large-eddy Simulation in-house code was used for the simulation of bubble plumes. The code has been developed with the purpose of obtaining a highly accurate and reliable CFD tool and yet very optimized in terms of time and computational resources so that it can be applied to practical engineering cases. These developments are, a strongly-coupled Lagrangian Particle Tracking (LPT) algorithm operating in an Eulerian flow field and a hybrid MPI-OpenMP parallelization strategy that alleviates the enormous computational overhead of the LPT routines. A new mapping approach for Eulerian-Lagrangian Large-eddy Simulation of bubble plumes based on delta functions is proposed and its performance is compared with distance-weighted linear interpolation. The accuracy of the two procedures in terms of time-averaged slip velocity is assessed with the aid of experimental data, and its influence on the plume shape discussed. Furthermore, the influence of bubble diameter on the dynamics of the plume and the time-averaged carrier phase velocity is shown and discussed.