Abstract The performance of a submerged cylindrical point absorbing wave energy converter was explored under the addition of different nonlinear stiffness (bistable) conditions. The limitations of previous studies were addressed by incorporating higher-fidelity modelling. Devices employing bistability in other energy harvesting applications, have improved the amount of power generated. For wave energy converters, most theoretical models with bistability were limited to one-degree-of-freedom, neglect nonlinearities such as viscous drag, and are excited by unrealistic sinusoidal waves. Such simplifications lead to neglecting features such as modal interactions. The presented model investigated a three-degree-of-freedom submerged point absorber with bistability subjected to regular and irregular waves. The bistable mechanism was an adjustable magnetic model such that a range of potential profiles were examined and parameterised, for generality, by features common between mechanisms. For this device, bistability may be used to obtain near optimal results and was suitably robust for changing ocean conditions. Regions of improvement were identified in terms of the changing natural frequency due to a nonlinear stiffness, and a phase matching property. In varying sea-states, a selected bistable condition demonstrated a 10–20% improvement in power production. The consistency implies that semi-active elements may be able to adjust the bistability to enhance power production.

中文翻译：

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利用双稳态增强潜波能装置的性能

摘要 研究了不同非线性刚度（双稳态）条件下水下圆柱点吸波换能器的性能。通过结合更高保真度的建模解决了先前研究的局限性。在其他能量收集应用中采用双稳态的设备已经提高了产生的电量。对于波浪能转换器，大多数具有双稳态的理论模型仅限于一自由度，忽略了粘性阻力等非线性因素，并由不切实际的正弦波激发。这种简化导致忽略诸如模态交互之类的特征。所提出的模型研究了一种三自由度浸入式吸收器，该吸收器具有受规则和不规则波影响的双稳态。双稳态机构是一个可调节的磁性模型，因此为了一般性，可以通过机构之间的共同特征来检查和参数化一系列潜在的轮廓。对于该设备，双稳态可用于获得接近最佳的结果，并且对于不断变化的海洋条件具有适当的鲁棒性。由于非线性刚度和相位匹配特性，根据不断变化的固有频率确定了改进区域。在不同的海况下，选定的双稳态条件表明发电量提高了 10-20%。一致性意味着半主动元件可能能够调整双稳态以提高功率产生。双稳态可用于获得接近最佳的结果，并且对于不断变化的海洋条件具有适当的鲁棒性。由于非线性刚度和相位匹配特性，根据不断变化的固有频率确定了改进区域。在不同的海况下，选定的双稳态条件表明发电量提高了 10-20%。一致性意味着半主动元件可能能够调整双稳态以提高功率产生。双稳态可用于获得接近最佳的结果，并且对于不断变化的海洋条件具有适当的鲁棒性。由于非线性刚度和相位匹配特性，根据不断变化的固有频率确定了改进区域。在不同的海况下，选定的双稳态条件表明发电量提高了 10-20%。一致性意味着半主动元件可能能够调整双稳态以提高功率产生。