A non-hydrostatic model for wave evolution on a submerged trapezoidal breakwater

Abstract

A depth-averaged non-hydrostatic model is formulated to investigate wave evolution on a water channel with a submerged trapezoidal breakwater. This model is an extension of nonlinear shallow water equations that includes hydrodynamic pressure and vertical velocity. In the momentum equation, a diffusion term is also considered to represent the turbulence effects in the system. The equations are solved numerically using a combination of a staggered finite volume method and predictor–corrector procedure. Comparisons are made against three independent laboratory experiments of wave propagation over submerged breakwaters. The level of agreement is higher than with Boussinesq-type and RANS models. The numerical scheme is also used to study the effect of the height, length, and diffusion coefficient of the breakwater on wave propagation. We have found that those characteristics affect the wave similarly by smoothing the wave shape and significantly reducing the transmitted wave amplitude.

Keywords

• Wave propagation
• Non-hydrostatic model
• Predictor–corrector procedure
• Composite-slope trapezoidal breakwater