CFD modelling of selected laboratory turbidity currents

Abstract

A Computational Fluid Dynamics (CFD) investigation was conducted to evaluate the accuracy and validity of the algebraic slip model in predicting the evolution of turbidity currents. The scenario used to run the model simulation was an experimental lock release of mono-disperse and bi-disperse turbidity currents. The general flow structure of the simulated currents compares well with the general experimental observation. The model used predicts the deposition from currents carrying coarse particles relatively well but excessively over-predicts the deposition rate in currents carrying fine particles. Incorporation of the Simonin model turbulence dispersion into the original model reduces the sediment deposition rate but incurs an excessive dispersion force. Thus, still another turbulence modulation model was incorporated into the finally proposed version and the mono-disperse flow was then re-simulated, and yet only small changes were observed in the results. It is concluded that improved results will be achieved by using more accurate turbulence dispersion models.