Wave Energy Convertor for Bilateral Offshore Wave Flows: A Computational Fluid Dynamics (CFD) Study

Abstract

Human activities have adversely affected the Earth’s habitable environment. Carbon emissions and other greenhouse gas emissions are the primary cause of climate change and ozone layer depletion. In addition, the exponential decay of fossil fuel resources has resulted in the rising demand for renewable and environmentally-friendly energy sources. Wave energy is the most consistent of all intermittent renewable energy sources and offers a promising solution to our energy needs. This study focuses on harnessing offshore wave energy resources, specifically targeting offshore conditions with the highest energy density. A novel direct drive cross-flow turbine with an improved augmentation channel shape was designed and analyzed using commercial computational fluid dynamics software. The turbine’s base model reached a maximum efficiency of 54.3%, with 33.4 kW of power output at 35 rev/min and a 3.0 m head. Bidirectional flow simulations were carried out, and the peak cyclic efficiency was recorded at 56.8% with a 36.4 kW average power output. The nozzle entry arc angle of 150 degrees was found to be the most efficient, and the numerical simulation’s fully developed solution computed the flow behavior through the runner and nozzle under steady-state conditions.