A Comparative performance analysis of heaving point absorber and oscillating wave surge type wave energy converters in irregular Sri Lankan wave conditions

Abstract

As an island surrounded by the Indian Ocean, Sri Lanka has significant potential to harness wave energy as a renewable energy source. However, limited research has been conducted on suitable wave energy converter (WEC) types under local wave conditions. This study analysed the performances of two main WEC types: Heaving Point Absorber (HPA) and Oscillating Wave Surge Converter (OWSC) in a sea location near Matara, a southern coastal area of Sri Lanka. The HPA performance was evaluated using a conventional cylindrical buoy and a novel super cuboid shape, which was found more efficient in previous studies. Similarly, for the OWSC, conventional rectangular flap was compared with a novel concaved flap geometry, also previously proven to be more efficient. The analysis employed Smoothed Particle Hydrodynamic (SPH) numerical simulations, with 266 simulations conducted under various operational conditions, including damping coefficients, Buoy Height to Wave Height Ratio (BHWHR), and buoy or flap widths. Results indicated that using a super cuboid buoy and concaved flap could increase the capture width ratio (CWR) by up to 25% compared to conventional geometries. The study concludes that HPA-type WECs are the best candidates for local wave conditions, considering CWR, hydrodynamic forces, and directional variations of the waves.