Numerical Wave Flume With Smoothed Particle Hydrodynamics (SPH) Method

Wave is one of the primary factors of coastal hydrodynamics. Wave's propagation, transformation, breaking and their interactions with structures are important in coastal engineering. The numerical wave flume is an effective method in wave study and able to simulate the wave motion better while the NS equation is used.A two-dimensional hydrodynamic model is developed, on the basis of studying thoroughly on the principle of Smoothed Particle Hydrodynamics (SPH) method and applying the numerical approximation formulations of SPH to NS equation. Some key issues of model are discussed and a new Nearest Neighboring Particles Searching (NNPS) technique is developed, which can improve the computation efficiency remarkably. The cases of the dam breaking, the solitary wave due to water collapse, and wave's splash and amalgamation are used to verify the present model.A two-dimensional numerical wave flume is established with SPH method. Solitary waves, nonlinear waves and irregular waves are generated. Comparisons of modeling results with analytical solutions and experimental results show satisfactory agreements. Waves generated by the numerical wave flume have obvious nonlinearity and decadent with propagations, which agree well with the laboratory flume. The signals of piston type plane are discussed. An artificial viscosity wave-absorber is developed, and computations reveal it is effective in treating the infinitely boundary conditions.The numerical wave flume is applied to study the interaction between solitary waves and the vertical wall, the wave run-up and run-down on a slope, and the propagation of a plunging breaking wave. The modeling results show that the SPH method is feasible to simulate the hydrodynamic problems with complex free surfaces, and the present numerical wave flume is suited to the close-up examinations of the near- shore wave problems.