In this thesis, Smoothed Particle Hydrodynamics (SPH) method is used for modeling dissipation of wave energy with horizontal perforated plate placed under water surface in a towing tank. Previous research using two-dimensional linear potential theory and Darcy’s law is improved with Navier-Stokes equation. The developed SPH formulation applied to dam break and wave maker problems in order to validate the formulation. Validation was achieved through comparison of numerical and experimental results existed in the literature. A new particle neighbor search is also developed and used for reduction of simulation time and the computational cost of model. Furthermore, parallel processing is used for decreasing time of simulation. The reduction of computational cost of modeling was important aspect in this research in order to be able to reduce the particle size or in another word increase the number of particles. As a result, the model was capable of handling up to one hundred thousand particles, small enough to pass the hole of perforated plate. The simulation of dam break, wave maker, and wave reflection from a vertical wall are used to verify the parallel-processed two dimensional codes, written in C language. Variation of wave front position with respect to time shows a good agreement with laboratory data reported in the literature and indicates well-behavioral characteristics compared to experimental data of Shao and Lo (2003). Simulation of piston wave maker shows that the wave maker introduces regular wave perfectly, which is the indication of stability and accuracy of SPH method. Effect of artificial viscosity, frequency, and Mach number on reflection coefficient from a vertical wall is also investigated. If artificial viscosity is used, wave reflection coefficient from the vertical wall decreases from 0.96 to 0.67. The calculation of reflection coefficient is based on method introduced by Goda and Suzuki (1976) for generation of regular wave. Wave reflection coefficient value is sensitive to wave frequency and Mach number. As a last and most complicated problem, the horizontal perforated plate with forty percent porosity is located at the water surface, close to the end wall of the towing tank was simulated using complete 2-D Navier-Stokes equations. Results of perforated plate modeling were compared with Cho and Kim (2008) experimental data. The wave profiles are in good agreement with reported experimental data. It is found that the reflection coefficient of 0.62 and 0.71with respect to the dimensionless ratio of plate length to wavelength matches closely to the results of experimental data. In addition, the reduction of wavelengths (in case of constant plate length) reduces the reflection coefficient, which means that perforated plate effectively interact with surface waves to lessen the wave reflection.
