A coupled SPH–DEM model for erosion process of solid surface by abrasive water-jet impact

As a meshfree method, the smoothed particle hydrodynamics method (SPH) is suitable for fluid–particle–solid (FPS) interaction problems, such as abrasive water-jet (AWJ) impacting process. However, the fully resolved SPH model requires fine resolution of discrete particles and the computation is expensive. The coupled method of SPH and discrete element method (DEM) may be a more effective approach. A coupled SPH–DEM unresolved model is proposed in this study for AWJ simulation, which containing water-jet flow, metallic solid and abrasive particles. The fluid and solid phases are discretized with SPH particles, and the abrasives are described by the DEM method. The coupling between SPH and DEM is achieved based on the so-called local averaging techniques. To enforce the efficient interaction between SPH–DEM and SPH–SPH, a double-layer linked-list neighboring particle searching procedure is proposed for establishing particle-pair in each time step, resulting in diverse smoothing lengths in the domain. Four numerical cases are conducted to verify the model’s applicability including single/multiple particle sedimentation and continuous/discontinuous AWJ impact. The erosion process of plastic deformation, failure and material removal by AWJ impact is reproduced. The new coupled model has more computational efficiency. Results show that discontinuous AWJ has less erosion rate and more energy efficient than continuous AWJ. The effects of distance between adjacent water columns on crater profiles by discontinuous AWJ is also involved. This model has more efficiency to be suitable for the research of AWJ and complex fluid particle flow.