The hydrodynamic characteristics of a dual-chamber oscillating water column device system with a gap between each unit is considered in this paper. A theoretical model is established to explore its wave power extraction performance under the framework of linear water wave theory and matched eigenfunction technique. A numerical strategy of successive approximation is utilized to seek for the optimal turbines combinations for the optimal energy absorption efficiency. Effects of the total chamber breadth, lip-wall drafts, breadth ratio for front and rear unit and gap length on the wave power extraction efficiency are explored and analysed. It is found that a larger total chamber breadth is more beneficial for the wave power extraction both for short and long wave regimes, and when the front and rear unit breadth ratio is 2/3, a more desired efficiency distribution could be obtained. Though the increase of lip-wall drafts (except for the most front one) could lead to a more satisfactory peak efficiency value and a much broader effective frequency bandwidth, the superiority of present system lies in the condition with relatively smaller lip-wall drafts in contrast to the single-chamber one. In addition, the gap length can effectively contribute to the formation of multiple peak efficiency values at the short wave regimes, especially under the condition that with a large gap length and significant improvement of efficiency could be achieved within a specified range of wave frequencies.

本文考虑了双腔振荡水柱装置系统在每个单元之间都存在间隙的流体力学特性。建立了一个理论模型，在线性水波理论和匹配特征函数技术的框架下，探讨其波功率提取性能。利用逐次逼近的数值策略来寻找最佳涡轮机组合，以获得最佳能量吸收效率。探索并分析了总腔室宽度，唇壁吃水量，前后单元的宽度比和间隙长度对波功率提取效率的影响。发现在短波和长波两种情况下，较大的总腔室宽度对波功率提取都更有利，并且当前后单位宽度比为2/3时，可以获得更理想的效率分布。尽管唇壁吃水量的增加（最前端的除外）可能会导致更令人满意的峰值效率值和更宽的有效频率带宽，但是本系统的优势在于，在这种情况下，唇壁吃水量相对较小。与单腔室相比。此外，间隙长度可以有效地有助于在短波状态下形成多个峰值效率值，特别是在间隙长度较大且在指定的波频率范围内可以实现效率显着提高的情况下。尽管唇壁吃水量的增加（最前端的除外）可能会导致更令人满意的峰值效率值和更宽的有效频率带宽，但是本系统的优势在于，在这种情况下，唇壁吃水量相对较小。与单腔室相比。此外，间隙长度可以有效地有助于在短波状态下形成多个峰值效率值，特别是在间隙长度较大且在指定的波频率范围内可以实现效率显着提高的情况下。尽管唇壁吃水量的增加（最前端的除外）可能会导致更令人满意的峰值效率值和更宽的有效频率带宽，但是本系统的优势在于，在这种情况下，唇壁吃水量相对较小。与单腔室相比。此外，间隙长度可以有效地有助于在短波状态下形成多个峰值效率值，特别是在间隙长度较大且在指定的波频率范围内可以实现效率显着提高的情况下。