Smoothed Particle Hydrodynamics (SPH) is one kind of mesh-free method with excellent adaptive nature for simulating fluid motion. A two-dimensional numerical wave flume is established with SPH method. An absorbing wavemaker boundary condition for particle method and layout of sponge layer are present. The capacity of absorbing second reflecting waves and incoming waves for absorbing wavemaker and sponge layer is validated through comparison of the numerical results with general wavemaker and solid boundary, respectively.
SPH is a relatively new numerical method developed in computing fields of hydrodynamics. It is a mesh-less and pure Lagrangian method using a series of particles to simulate continuum fluid and estimate the relevant partial differential equations. It can overcome many problems existing in grid-based approach during solving process (Benz, 1989; Benz, 1990; Monaghan, 1992; Sun 2007). The numerical wave flume is one of the main tools to research problems such as wave breaking and wave-structure interactions in coastal areas (Lo, 2002; Dalrymple and Rogers, 2006). However, the multiple reflections of waves in traditional numerical flume reduce the accuracy and reliability of the model. Therefore, absorbing wavemaker and sponge layer are put forward to absorb the second reflecting waves from the wavemaker and the incident waves respectively. Liu and Zhao (1999) developed a numerical wave flume based on NS equation and the finite-element method, in which the open boundary used Sommerfeld's radialization boundary conditions and artificial attenuation layer, and around the incident boundary, a speed attenuation region was set to absorb secondary reflected waves. Shi et al. (2004) set up a numerical wave flume based on the Laplace equation and boundary element method, in which waves were made by the wave-making paddle, using Mitsuyasu-Bretschneider spectrum as the control signals, and the virtual wave absorbing and permeable layer were set at the open boundary.
