Model Experiments on Waves and Nearshore Currents around Floating Wave Power Plant in Coastal Waters in Comparison with Detached Breakwater

Abstract

The role of a floating wave power plant in the environmental control of coastal waters for coastal fisheries is discussed. An experimental investigation was carried out into the physical characteristics, i.e. waves and wave induced nearshore current around a model of a floating wave power plant on an inclined bottom in comparison with a model of a detached breakwater. The results are summarised as follows: (1) The floating wave power plant can be utilised for environmental conservation and the progress of coastal fisheries to create calm sea areas, improve water quality, control nearshore currents and provide power for aeration and dipping out of bottom waters. (2) The calm water area behind the floating power plant model where wave transmission ratio is less than 0.5 in three dimensional condition is almost the same as behind the detached breakwater. (3) The calm water area becomes wider near the shore line as the bottom slope becomes more gentle. (4) The reflected wave height at the front of the floating power plant model is much smaller than the detached breakwater. (5) Circulating current on free surfaces from the centre of the model to the outer side of the floating power plant model is dominant near water surface, it is dominant from the outer side to the centre of the model of the detached breakwater. In particular, strong currents toward the shore line just behind the floating wave power plant model was observed. (6) Water exchange near the floating wave power plant model is larger than the detached breakwater. It becomes larger as the bottom slope becomes more gentle for both models.