Hydrodynamic performance of a heaving oscillating water column device restrained by a spring-damper system

The performance of a heaving oscillating water column (OWC) device restrained by a spring-damper system is explored based on linear wave theory. The matching conditions along the common interfaces are employed, and the power take-off model and heaving motion equation are incorporated into the solution procedure. The device, allowed fully-free heaving, restrained by a linear spring and by a spring-damper system, are successively examined under the ideal turbine condition. To achieve practical sense, the performance between different types of devices from a practical turbine strategy is compared as well. The results show that the proper spring value is not only helpful for triggering dual peak effi-ciencies, but also for expanding the frequency bandwidth relative to the fully-free heaving device. Though the extra inclusion of the damper system can only supplement power extraction, it is beneficial for reducing the horizontal loads on the front lip-wall thus enhance the structure safety. Additionally, under the practical turbine strategy, the heaving device restrained by a spring-damper system is more flexible to be deployed in the maritime spaces dominated by waves with different frequencies relative to the stationary device.(c) 2022 Elsevier Ltd. All rights reserved.