Numerical analysis of hydrodynamic performance of a dual-chamber Oscillating Water Column

Due to limited fossil energy resources and environmental pollution, the global demand for green and safe renewable energy is growing. The ocean waves are one of the most important kinds of renewable energies. Oscillating Water Column (OWC) is one of the most applicable and well-known devices among the wave energy converters. In this research, a dual-chamber OWC is investigated and the results are compared with the single-chamber results. The waves are generated by using linear Airy or nonlinear second-order Stokes theories. The 2D RANS equations are solved using ANSYS-Fluent software. After validating the used method and schemes with the experimental data the hydrodynamic efficiency of the dual-chamber OWC is investigated for different chamber lengths and the results are compared with the results of the single-chamber device. Also, the performance of the dual-chamber OWC with stepped sea bottom is investigated and the effect of the step dimensions on the efficiency of the OWC is studied. Moreover, the results show that the dual-chamber OWC usually has better hydrodynamic efficiency and this better performance is more obvious in small wavelengths. The maximum efficiency of dual-chamber OWC is reached to 67.1% for the optimized stepped bottom device for the dimensionless wave No. kd = 1. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This research compares the efficiency of dual-chamber and single-chamber OWCs, and investigates the effects of different chamber lengths and stepped sea bottom on their efficiency. The experimental results show that the dual-chamber OWC usually has better hydrodynamic efficiency, especially evident in small wavelengths.