Numerical experiments of breaking waves on dissipative and intermediate beaches using a two-phase flow method

A fully coupled two-phase flow model was developed to simulate nearshore fluid-sediment turbulent flow. It includes the Reynolds-Averaged Navier-Stokes equations and turbu¬lent stress closures for each phase, and accounts for inter-granular stresses. It was used to simulate wave breaking and the ensuing hydrodynamic and sediment transport processes in the surf/swash zones. Spilling and plunging breakers occur on dissipative and intermediate beaches, re-spectively. The impact of these wave/beach types on nearshore zone hydrodynamics and beach morphology was determined. The numerical results show that the turbulent kinetic energy, sediment concen¬trations and transport rate are greater on intermediate than on dissipative beaches. The results are consistent with existing physical understanding, suggesting that the two-phase flow model is suitable for the simulation of mixed water-sediment flows in the nearshore. The model has potential as a useful tool for investigating interactions between nearshore hydrodynamics and beach morphology.