DEVELOPMENT OF A NUMERICAL MODEL  FOR ANALYSING THE HYDRODYNAMIC PERFORMANCE  OF OCEAN WAVE ENERGY CONVERTERS  FOR POWER GENERATION APPLICATIONS

Given the critical need for sustainable energy alternatives to achieve net-zero targets, wave energy emerges as a promising option due to its high energy density and constant availability. Despite its potential, existing Wave Energy Converter (WEC) technologies  require significant improvements to lower the Levelised Cost of Energy (LCoE) and compete with other renewable sources. In this context, this thesis presents the development of a mesh-free-based numerical model aimed at optimising the hydrodynamic performance of WECs for effective power generation. Two WEC types were investigated: the Oscillating Wave Surge Converter (OWSC) and the Heaving Point Absorber (HPA), under different wave conditions, with particular focus on Sri Lanka’s wave climate. Initially, optimisation was carried out using regular waves across a wide frequency range, including the analysis of peak performance versus natural frequencies of the WECs. Subsequently, a comparative analysis was performed under the wave conditions of the southern coastal area of Sri Lanka. By leveraging the advanced numerical modelling capabilities of the meshfree method Smoothed Particle Hydrodynamics (SPH), numerical models of WECs were developed  using the open-source, state-of-the-art DualSPHysics software framework. The models were validated for power output and efficiency predictions, and then used to optimise key operational parameters such as flap and buoy geometries, density of the flap or buoy, the  damping coefficient of the Power Take-off (PTO), and device dimensions. For the OWSC, optimised flap designs combined with PTO damping adjustments  were found to significantly improve the Capture Width Ratio (CWR). For the HPA, PTO damping, buoy geometry, and the Buoy Heave-to-Wave Height Ratio (BHWHR) were identified as critical parameters for maximising energy absorption while simultaneously controlling hydrodynamic forces that influence structural loads, with direct implications for both capital and maintenance costs. Flow patterns and pressure distributions around the buoys and flaps were also analysed to  provide better insight into wave–structure interactions and performance drivers. Notably, concave-shaped flaps increased CWR by up to 45%, while the novel “Super Cuboid” buoy shape enhanced efficiency by up to 25%. Comparative analysis under Sri  Lanka’s wave conditions demonstrated the adaptability of both WEC types, with each device offering unique advantages under varying environmental and operational scenarios. By introducing the “Super Cuboid” buoy and “Concaved Flap” geometries alongside optimised operational parameters, this study provides a novel application of high-fidelity SPH methods for both geometry and operational optimisation in WEC research, laying the groundwork for more efficient, cost-effective designs for real-world applications.