Development of Numerical Model for Hydrodynamic and Morphology Evolution Under Wave and Current Conditions Based on Openfoam®

A 2-D full-coupled hydrodynamic and morphology CFD model is developed and improved based on OpenFOAM®. Two physical experiments are used to validate the model: breaking solitary wave on a sloping beach (Sumer et al. 2011); local scour beneath a pipeline under steady flow (Mao 1986). The numerical model is based on incompressible Reynolds-averaged Navier-Stokes equations and incorporated with volume of fluid (VOF) method, k-omega turbulence closure, and sediment transport model (both for bed load transport and suspended load transport). The bed evolution is tracked by dynamic mesh method. A new near wall treatment for suspended load transport, which proposed by Liu (2013), is implanted in this model. The hydrodynamic model is validated against the rigid-bed case of the breaking solitary wave experiment. The numerical results of wave surface elevation and bed shear stress agree well with those obtained from the experiments. Then the sediment transport model is validated under both solitary wave and steady flow experiments. The quantitative agreement between computed sediment bed profile and experiment results are satisfactory, despite a slight underestimation of the erosion depth in solitary wave case. The results show that the numerical model can well simulate hydrodynamic and morphology involved in coastal and ocean engineering problems, such as beach erosion and local scour under subsea pipeline.