Abstract
Wave energy conversion is a promising technology to provide renewable energy, but its commercialization is limited mainly due to high initial investment and maintenance cost. One way to improve the economic feasibility of wave energy utilization is to integrate wave-energy converters (WECs) into shore-protection structures to form dual-function structures, which have the capability to harness wave energy for electricity generation and provide coastal protection. Among different types of existing WECs, oscillating water columns (OWCs) have the power takeoff (PTO) system out of water, which greatly reduces the influence of befouling on PTO performance and lowers maintenance cost. This study introduces a dual-function design by integrating an OWC-type WEC with a bottom sitting slotted barrier. For these types of dual-function structures, the main design objectives are to achieve the designed transmission coefficient, maximize the wave power extraction, and minimize the wave loading on the structure. In this study, we present preliminary results of an experimental study of the proposed dual-function structure in a small wave flume equipped with a piston-type wave generator. In the experiment, a circular orifice at the top of the pneumatic chamber was utilized to emulate the PTO system. Wave power extraction was measured using a differential pressure sensor. Wave loading on the structure was measured using a single-axis force balance. The focus of this study is to observe the effects of tide level and the porosity of the slotted barrier on the wave power extraction, wave transmission and wave loading under different wave conditions. Two slotted barriers and two water depths were studied. Main results reported include reflection, transmission and energy loss coefficients, wave power extraction efficiency, and wave loading.
