Numerical Simulation Of Dam-break Flow Using Incompressible Smoothed Particle Hvdrodvnamics Methods

Normally, the propagation of flood is associated with hydraulic erosion and sediment transportation, the reasonable description of free surface and sediment movement remains one of the research hotspots and difficulties. Smoothed particle hydrodynamics method(SPH) is an increasingly conventional mesh-free method for several decades. It can provide accurate and stable numerical solutions to problems with free surface and water-sediment large deformation due to its Lagrangian nature. Compared to traditional SPH method, the constraint of density invariance is introduced to the ISPH method to provide theoretically incompressible results which is also closer to reality. In this study an incompressible smoothed particle hydrodynamics (ISPH) approach coupled with the sediment erosion model was developed to investigate the sediment bed scour and grain movement under the dam break flows. The sediment bed erosion model was based on the concept of pick-up flow velocity which was derived from the critical flow velocity for incipient motion. The proposed model was used to reproduce the sediment erosion and follow-on entrainment process under an instantaneous dam break flow and the results were compared with those from the weakly compressible moving particle semi-implicit (WCMPS) approach as well as the experimental data. It has been demonstrated that the proposed ISPH model performed well with the experimental data.The highlights of this article are listed below:(1) ISPH method based on density invariance was initially adopted for sediment scouring, the ISPH erosion model was applied to two dam break flow tests and validated, error norms were quantified between ISPH simulations and documented data.;(2) A critical pick-up velocity concept was used to initiate sediment movement, sensitivity analysis was made for particle spacing and pick-up velocity.