非线性波作用下振荡水柱式波能转换装置的高效能

Since the 1970s, the wave energy conversion technology has received vigorous development. Oscillating water column wave energy converter, as one of them, is the most popular and promising. Based on the combination of theoretical analysis and numerical simulation, the performance of oscillating water column wave energy converters under weakly nonlinear wave theory is developed. By employing the perturbation principle, the coupling of nonlinear waves is investigated, and the wave cancellation conditions are obtained as well. Moreover, a method of matched eigenfunction expansions is adopted. For the sake of improving the numerical convergence and precision, the singular behavior of flow is incorporated mathematically based on the orthogonality of polynomials and trigonometric functions. In addition, the evaluation of energy dissipation due to vortex-shedding and the rule of suppressing vortex-formation are obtained by CFD software. The aim of this study is to solve the bottleneck problem of the poor economic performance and low extraction efficiency, and to help the engineering design and application of wave energy conversion technologies.

基于摄动法原理，深入研究非线性海洋表面波的耦合作用及消波机理。再借助正交多项式，近似表征流体流动在结构大变形处的奇异行为，有效提升数值计算中的收敛速度和精度。通过与相关线性结果进行对比分析，阐明高阶波耦合作用对转换效率的影响机理。随后，数值模拟分析不同波况下涡的生成和脱落机制，据此评估涡脱落造成的能量耗散体系并提出抑制方法。由以上，即可阐明非线性波的耦合机理对转换效率的影响，评估非线性波作用下涡脱落造成的能量耗散，并提出抑制涡生成的方法，为突破波浪能装置“转换效率较低”的瓶颈提供理论指导，从而有效促进目前极具广泛应用前景的振荡水柱式(OWC)波浪能转换装置技术。

随着全球气候变暖、环境恶化和传统化石燃料的逐步枯竭，寻找绿色可再生替代能源已成为世界各国的关注热点。本项目以振荡水柱（OWC）波能转换装置为研究对象，采用理论分析、模型试验和数值模拟相结合的方法，开展非线性波诱导下装置增效机理的研究。基于共振原理，发展波浪-可运动前墙OWC装置相互作用的水动力模型理论，探索波浪驱动下前墙相对运动和腔室内水体振荡这两种简谐系统间的耦合机理，提出满足该装置安全、高效的控制策略和合理的结构配置型式；剖析波浪非线性对装置俘获宽度比和高效频率带宽的影响机制，评估所提出的俘获宽度比增大和高效频带拓宽技术的有效性；揭示波浪诱导下装置结构底部附近因旋涡生成和脱落造成的粘性耗散机制，建立粘性耗散的评估体系。所发展的理论与技术创新及获得的原创性成果对于振荡水柱波能转换装置的效率提高，具有重要的指导意义。