Improved performance of land-fixed oscillating water column through dual chamber design

Abstract

Improvements to the hydrodynamic efficiency of oscillating water columns (OWC) have the potential to influence commercial OWC adoption. The main goal of this study is to determine whether dual chamber OWCs with either a shared turbine or dual turbines can improve the hydrodynamic efficiency of the OWC through two-dimensional numerical simulations using computational fluid dynamics. In the numerical simulations, water depth is 0.8 m and the total length of the two chambers is 0.6 m. Numerical results show that when the non-dimensional turbine coefficient is 0.192, 1.432, and 3.070, a dual chamber dual turbine configuration can achieve between 7.6% to 26.8% greater hydrodynamic efficiency than both the single chamber single turbine and the dual chamber shared turbine configuration. Dual chamber, dual turbine configurations can increase hydrodynamic efficiency by operating over a broader range of wavelengths due to multiple resonant frequencies and are not affected by phase differences at shorter wavelengths.