Experimental Study of an Overtopping Wave Energy Converter

• Main Authors: Chih-Peng Lu, 盧志朋
• Other Authors: 蔡進發
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/cbuaz9

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 105 === The purpose of this study is to evaluate the performance of an overtopping wave energy converter by model test. A 1/25 overtopping wave energy model, which was designed by the National Chung-Shan Institute of Science & Technology, was made to conduct the performance test. A series of tests, based on the similarity laws which include geometry, kinematic and dynamic similarity law, were conducted in the towing tank of National Taiwan University. The tested wave conditions were determined from the statistical data of Long-Dong buoy which is located in northeastern Taiwan during 1998 and 2005. The motions and efficiency of the overtopping wave energy converter were evaluated by the selected wave conditions. The test results show that the non-dimensional overtopping flow rate is different from empirical formula developed by Kofoed. More wave conditions were conducted to find the empirical formula for the overtopping wave energy converter. The motions of the overtopping wave energy converter were studied in this study to get the response amplitude operator(RAO) of pitch and heave of the overtopping wave energy converter. The pitching and heaving of the overtopping wave energy converter with full and empty reservoir were also measured. The measured results show that the resonance frequency of the pitch RAO is about 0.74 Hz. The corresponding wave length is about 2.85 m which is near the length of the wave overtopping energy converter model. The water accumulated in the reservoir reduces the pitch and heave RAO when there is non-overtopping. The overtopping water increase the pitch and heave RAOs when the wave frequency is greater than the resonance frequency 0.74 Hz. The maximum value of the measured mooring force in the duration of a test was chosen for the analysis of the mooring force. The scheme of the wave impact loading on buildings and structures, which was developed by Chen. was utilized to analyze the mooring force of the system. The results show the mooring force majorly determined by the incident wave height, wave period and the freeboard of the system.