Utilization of Wave Dissipating Caissons as an OWC Type Wave Energy Convertor

Abstract

Wave energy convertors (WEC) of oscillating water column (OWC) types make compressed air due to vertical movement of a part of water column, which are surrounded by some walls in water. As a result, the compressed air works to rotate an air turbine which also works for an electrical generator. If a structural system can make to move water such like a water column, a shape of a structure would not matter. Wave dissipating caissons installed in or on the existing production line can make to transfer a water wave to a flow and to reduce wave energy by making to overflow them. The caissons which can be overflowed by the water would actuate a water region vertically such like an oscillating water column system. This study investigated if we can utilize wave dissipating caissons as a WEC. Wave dissipating caissons also decrease wave energy due to passing through themselves. Even so, when an air turbine can be installed onto the caisson in order to harvest wave energy, it would be possible to produce electricity at low cost. The study conducted model experiments using the model assumed that wave dissipating double-caissons were remodelled to OWC type WECs with side walls and evaluated performance of the primary conversion of them. In addition, effects of how to arrange the number of the WECs on the primary conversion efficiency were investigated with theoretical calculations based on the linear potential theory and the possibility of utilization of wave dissipating caissons as a WEC was examined in the study.