底铰摇板式波浪能装置水动力性能解析研究

Analytical study on hydrodynamic performance of wave-power device with bottom-pivoted flap

对底铰摇板式波浪能装置的水动力性能进行了解析研究,基于受约束浮体线性化运动方程,获得小幅线性波作用下装置动力响应和转换性能的解析解;采用解析解计算分析了水深、厚度、密度和PTO阻尼值四个参数选取对装置转换性能的影响。研究结果表明,底铰摇板式波浪能装置具有较宽的频率响应范围;在低频区,水深较大时装置俘获效率较高,而在高频区,水深较小时装置俘获效率较高;系统性能受摇板厚度的影响非常小;密度较小的摇板在高频区性能较好,而密度较大的摇板在低频区性能较好;设置恒定PTO阻尼的情况下,装置性能受PTO阻尼值影响显著,当PTO阻尼取低频辐射阻尼时,装置的俘获效率与满足阻尼匹配条件的情况基本相同;当采用的PTO阻尼与低频辐射阻尼值差别较大时,系统的俘获效率显著降低。

A parametric study was carried out on the hydrodynamics of a bottom-pivoted flap wave energy device.The analytic solution was derived of flap′s motion and mechanism performance under small and linear wave,according to the general equation of restricted floating body.The influence of mechanism performance was analyzed about the value′s variation of water depth,flap thickness and flap density and PTO damping.The results show that the bottom-pivoted flap wave energy device has broad bandwidth response.In deep water the mechanism has large capture factor in the low frequency range,while in shallow water it has large capture factor in the high frequency range.The flap thickness has little influence on mechanism performance.The mechanism with smaller density flap has large capture factor in the low frequency range,while the mechanism with greater density flap has large capture factor in the high frequency range.While constant PTO damping value is used,the damping value has significant influence on mechanism performance.When the PTO damping approaches to the radiation damping of the device at low frequency,the capture width is approximately the same as that under matched damping condition.When the difference between B and b is evident,the capture width of the device decreases significantly.