Experimental and numerical investigations on the solitary wave actions on a land-fixed OWC wave energy converter

Abstract

The dynamic performance of a typical land-fixed oscillating water column (OWC) wave energy converter (WEC) under solitary waves (SW) is experimentally and numerically investigated. Both two-dimensional (2-D) and three-dimensional (3-D) numerical models are considered in the present study. The air orifices of the OWC chamber in 2-D and 3-D models are represented by a narrow rectangular opening and a circular opening, respectively, with the same opening ratio (i.e., the cross sectional area ratio between opening and the air chamber). It is found that the overflow of the orifice occurs when the wave height exceeds a threshold, which results in a larger wave force on the structure compared with that induced by the SW crest. The 2-D numerical model fails to predict the overflow phenomena due to the full submergence of the orifice. The overtopping and roof impacting phenomena are induced when the wave run-up exceeds the front wall height. A portion of the SW energy is released during this process. Hence, total wave forces are reduced. The effect of wave heights on force components exhibits different behaviors due to the coupling of air and water inside the chamber. Both the impacting force and overtopping discharge increase with incident wave heights.