Evaluation of Solid-Fluid interaction is of high significance in all engineering fields. In this paper, the Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM) were employed to simulate solids and fluids, respectively. As for the simulation of water behavior, first, a single-phase “dam break” experiment is modeled by the SPH. In this model, variable smoothing length and an almost novel boundary method were utilized which resulted in a tremendous boost in its resemblance to the experiment. To couple these methods (SPH and DEM), three approaches were proposed and validated against a famous experimental test named “dam break with an elastic gate test”. Finally, to be sure of the correctness of these approaches, an elastic plate under a water column in the hydrostatic condition was simulated and the error was 2 percent in comparison with the analytical solution. In pursuit of having short run-times, parallel computing on GPU (CUDA) was employed, and a robust nearest neighbor search (NNS) algorithm was modified and developed.

The current manuscript presents the validation of Smoothed Particle Hydrodynamics (SPH) techniques for wave generation by underwater explosion, utilizing the so-called Duals Physics numerical model. This numerical method is used to analyze generated waves which are initiated by man-made or natural explosions below free surface level of sea. In spite of the modeling limitations (e.g. absence of open boundary conditions), reasonable agreement is accomplished with predictions of the existing formula as well as experimental results. This proved that SPH techniques such as incorporated in Duals Physics are becoming a suitable alternative to existing classical approaches to this particular water waves problem. It is also provided an inherently more accurate computational for the prediction of wave characteristics generated by underwater explosions.

In this study, attempts to suppress numerical viscosity in incompressible smoothed particle hydrodynamics (SPH) computations are reported. Two-dimensional computations are performed for inviscid and viscous flows to evaluate the effects of numerical viscosity suppression. The first approach is to reduce numerical viscosity at the wall by considering only the wall-normal components of the forces between fluid particles and wall particles. The second approach is to reduce numerical viscosity within the flow field by employing elliptic kernel functions whose major axes are aligned with the local mean flow direction. It is found that special treatment of the wall radically reduces the numerical wall friction. Using an elliptic kernel function is found to work reasonably well in reducing numerical viscosity.

In this paper, the Shallow Water Equations (SWEs) are solved by the Smoothed Particle Hydrodynamics (SPH) approach. The proposed SWE-SPH model employs a novel prediction/correction two-step solution algorithm to satisfy the equation of continuity. The concept of buffer layer is used to generate the fluid particles at the inflow boundary. The model is first applied to several benchmark water flow applications involving relatively large bed slope that is typical of the mountainous regions. The numerical SWE-SPH computations realistically disclosed the fundamental flow patterns. Coupled with a sediment morph dynamic model, the SWE-SPH is then further applied to the movement of sediment bed load in an L-shape channel and a river confluence, which demonstrated its robust capacity to simulate the natural rivers.