底铰摆式波能装置在斜向波中的水动力性能

HYDRODYNAMICS OF BOTTOM-MOUNTED FLAP-TYPE WAVE ENERGY CONVERTER IN OBLIQUE REGULAR WAVES

采用特征函数展开和二维格林函数相结合的方法求解底铰等厚度摆式波能转换装置水动力系数及斜向规则波作用下的波浪扰动力矩。二维积分方程中奇异积分项采用复变函数解析法求解,因此同时适用于有限厚度及薄壁底铰摆板的水动力计算。通过与文献及与AQWA软件水动力计算结果的比较,验证程序的正确性。类似于船舶横摇运动,在固有周期附近粘性阻尼对摆式波能转换装置的性能有很大影响。通过在运动方程中添加粘性阻尼项考虑粘性阻尼的作用,并在此基础上给出最佳负载阻尼系数的估算公式,分析波向角和波高对装置最佳转换效率的影响。

The hydrodynamic coefficients of the bottom-mounted equal thickness flap-type wave energy converter and the wave exciting moment in oblique regular waves were calculated by the method combining two-dimensional Green＇ s function with eigenfunction expansion. The singular integral term in the two-dimensional integral equation was evaluated by using the analytic method of complex function, so it was suitable for the hydrodynamic calculation of the bottom- mounted finite thickness or thin wall flap-type wave energy converters. The accuracy of the present method was verified by comparing with hydrodynamic results in the literature and calculated by AQWA software. Similar to the ship rolling motion, the effect of viscous damping near the resonance period on the performance of a bottom-mounted flap-type wave energy converter was very large. The viscous effect was accounted by including a viscous damping term in the motion equation, also the estimate formula of the optimal load damping coefficient was given. The effects of the wave incidence angle and the wave height on the optimal conversion efficiency of device were analyzed.