Effects of Sea-Bed Undulation and Front-Wall Geometry on the Performance of a Bottom-Seated OWC Device

Oscillating water column (OWC) is a type of wave energy converter (WEC) device that extracts the ocean water energy by harnessing the periodic motion of the water waves and the subsequent pressure difference at the air water interface. The main advantages of such devices are their efficiency even at low wave frequencies, scope for hybridization with other systems like solar and wind energy converters, cost effectiveness and minimum to no negative impact on the environment. This study is based on a bottom-seated OWC device on an undulated seabed. Here, the effect of sea-bed undulation is studied for different geometrical configurations of the front wall of the OWC device to attain optimum hydrodynamic performance. Previous studies have neglected the effects of seabed undulation which generally occurs for real oceans. This physical problem is converted into a boundary value problem (BVP) under the linearized water wave theory and potential flow theory, which is then solved using the boundary element method (BEM). It has been found that numerical method like BEM provides better and more accurate solutions when the domain geometry is more complex as compared to analytical methods, which can't handle the complex domains. Physical parameters such as the slope of the front wall, the width of the chamber, and the bottom undulation are considered for the present investigation to obtain the optimized configuration for maximum power generation.