Numerical simulation of a stationary offshore multi-chamber OWC wave energy converter

This paper aims to study the improvement in hydrodynamic efficiency of an OWC device by dividing a single chamber into multiple chambers. The two-dimensional incompressible Reynolds-Averaged Navier-Stokes equations are solved to simulate the water motion due to waves and a compressible aerodynamic model is used to calculate the airflow through the turbine. Simulation of a dual-chamber-two-turbine (2C2T) case was first conducted using a range of turbine coefficients to identify the best turbine coefficient to be used for the rest of the study. The dual-chamber-dual-turbine configuration was found to increase the efficiency more than the case of two chambers sharing a single turbine (2C1T). The triple-chamber-triple-turbine (3C3T) configuration further increases the efficiency when compared with the 2C2T configuration. Despite achieving greater changes in free surface elevation, when compared with multi-turbine multi-chamber configurations, shared turbine configurations achieve lower overall efficiency due to phase differences in surface elevation between chambers. •Dividing single chamber into multiple chambers with total chamber length unchanged improves the hydraulic efficiency.•Using multiple turbines for multiple chambers further improve the hydraulic efficiency compared with using single turbine.•Sharing a single turbine has larger amplitudes of oscillating water surface but smaller efficiency than multiple-turbines.