非对称垂荡式振荡水柱波能转换装置的水动力性能

Hydrodynamic performance of an asymmetric oscillating water column wave energy convertor in heaving mode

为提升波能转换装置的经济竞争力,针对非对称垂荡式振荡水柱(OWC)波能转换装置,基于势流理论和匹配特征函数展开法,通过引入盖根堡多项式近似表征结构尖角附近的流场奇异性行为,深入研究后墙吃水深度(非对称)、墙体厚度和线性弹簧系数对垂荡式OWC装置的波能转换效率、透射系数、气室内平均液面高程等水动力参数的影响规律。研究结果显示,后墙吃水深度及墙体厚度的增加会提升装置在长波区域的高效转换能力,并且显著提高结构物整体阻波防浪性能;线性弹簧的出现,能调节水柱振荡和结构垂荡运动响应之间的相位差,从而有效拓宽垂荡式OWC装置的高效频率带。

In order to improve the economic competitiveness of the wave energy converters,based on the potential flow theory and matched eigenfunction expansion method,a semi-analytical model is established to investigate the hydrodynamic characteristics of an asymmetric oscillating water column(OWC)wave energy convertor in heaving.According to the geometric characteristics of corners,the Gegenbeuer polynomials are introduced to approximately represent the singular behavior.The effects of rear wall drafts(asymmetric),wall thickness and spring stiffness on the conversion efficiency,transmission coefficient,and averaged free-surface elevation in chamber are examined.The results show that increasing the back-wall draft and the wall thickness can enhance the absorption capacity of the device in long-wave regimes and significantly improve the overall wave absorption and prevention performance of the structure.The presence of the linear spring can be used to adjust the phase difference between the internal freesurface oscillation and the response of the device structure,and further be beneficial for broadening the high-performance frequency bandwidth of the heaving OWC device.