Numerical Analysis and Performance Optimization of a Flap-type Oscillating Wave Surge Converter in Irregular Waves

Renewable energy plays a vital role in ensuring the sustainability of the world. Among different renewable energy sources, wave energy is one of the least-developed technologies. Out of the available Wave Energy Convertors (WEC) the Oscillating Wave Surge Converter (OWSC) is one of the most researched types of WECs due to its higher performance characteristics compared to many other WECs. In this background, this research focused on DualSPHysics-based numerical prediction of the energy conversion efficiency (ECE) and survivability of an OWSC in irregular waves observed in a selected coastal location of Sri Lanka. It was found that the Power take-off (PTO) damping coefficient, the density of the oscillating flap and the shape of the flap highly influence the ECE and the hydrodynamic forces on the WEC deciding its survivability. If the density of the flap is in the range of 400 - 600 kg/m³ and its shape is more concave, the ECE increases significantly (about 25%) while improving its survivability. On the other hand, a significant reduction (25 to 47 %) in hydrodynamic forces could be achieved using cone or semicone-shaped flaps at the expense of ECE which would be a good alternative for high energetic seas.