Application of Method Processing and Strain Gauges to study the Wave Energy Converter Conversion Efficiency of a Double-hinged Flapper with A Hydraulic Cylinder

• Main Authors: Wu, Yan-Han, 吳彥瀚
• Other Authors: Tzang, Shiaw-Yih
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/70227259460112808028

碩士 === 國立臺灣海洋大學 === 河海工程學系 === 103 === In this paper, the Double-hinged Flapper with a hydraulic cylinder and six changable tube hinges and one fixed bottom hinge was experimentally studied for the effects of changeable hinges on conversion efficiency of wave power. The results were compared with those of a bottom-hinged flapper with a hydraulic cylinder. The power conversion efficiency was derived by multiplying angular velocity and the torque measured at the bottom hinge. The resulting power conversion efficiency was analyzed on its relation with incident wave power, wave steepness and Ursell number. Experimental tests adopted image methods to derive the rotating angles and and angular velocity of each changeable hinge. The Potplayer software was adopted to simplify analysis process. The strain gauges were applied at the ottom hinge to measure torque. The measured data were all processed with low-frequency filters to delete oscillating noisesa. Then, data of the angular velocity and torque were further synchronized to derive captured power. The joint distribution of wave heights and periods of the northeast monsoon from October 2013 to March 2014 were analyzed for selecting the five wave conditions with highest occurrence probability. The test data were claculated by Goda’s equivelent deep water-wave method and a scale of a ratio of 1/20 for experimental setups of a small-scale wave basin of 0.5 m in depth. The results clearly illustrate that the power conversion efficiencies are decreasing with increasing incident wave power and Ursell number. The highest power conversion efficiencies for the changeable hinge at the fourth and third positions are found to be about 35% and 21%, respectively. Comparisons with bottom-hinged flapper, the power conversion efficiencies of the Double-hinged flapper are found to be improved by about 2-5%.