Numerical modelling of complex turbulent free-surface flows with the SPH method: an overview

The gridless smoothed particle hydrodynamics (SPH) method is now commonly used in computational fluid dynamics (CFD) and appears to be promising in predicting complex free-surface flows. However, increasing flow complexity requires appropriate approaches for taking account of turbulent effects, whereas some authors are still working without any turbulence closure in SPH. A review of recently developed turbulence models adapted to the SPH method is presented herein, from the simplistic point of view of a one-equation model involving mixing length to more sophisticated (and thus realistic) models like explicit algebraic Reynolds stress models (EARSM) or large eddy simulation (LES). Each proposed model is tested and validated on the basis of schematic cases for which laboratory data, theoretical or numerical solutions are available in the general field of turbulent free-surface incompressible flows (e.g. open-channel flow and schematic dam break). They give satisfactory results, even though some progress should be made in the future in terms of free-surface influence and wall conditions. Recommendations are given to SPH users to apply this method to the modelling of complex free-surface turbulent flows. Copyright (c) 2006 John Wiley & Sons, Ltd.