Application of computational fluid dynamics (CFD) to model entrainment across a density stratified interface

A flexible floating bottomless containment has been considered as a potential means of keeping a freshwater separated from seawater in a river mouth or estuary. Viability assessment for such a scheme calls for study of entrainment across the density-stratified interface between the freshwater and the saltwater flowing underneath. Earlier research has considered this phenomenon by laboratory experiment. In the work reported here the commercial computational fluid dynamics modelling package FLUENT is used to simulate the entrainment process and the results are compared with earlier experimental findings. For this multi-phase flow process, the entrainment rate so synthesised numerically has been found to be capable of yielding good agreement with the test data only following a process of model parameter calibration and empirical adjustment. For this situation and at this point, FLUENT is, therefore, found to be capable of qualitative synthesis of the entrainment between the two fluids and discussion is made of problematic aspects of the current implementation of the numerical procedure.