Wave power extraction from slanted oscillating water columns in the presence of an array of arbitrary trenches

Abstract

This paper investigates the impact of arbitrary bottom topography on the efficiency of a slanted oscillating water column device located in near-shore areas. The device incorporates a turbine positioned at its opening, which harnesses the oscillation of the fluid at the free surface, created by recurrent incident waves, to propel an air volume in a uni-direction. To analyze the wave power absorption capability of the system, an eigenfunction expansion and a boundary element model based on linear water wave theory are employed. The notion is to use the anticipated amplification of scattered and reflected wave fields resulting from the existence of a sloping wall to improve the wave power absorption caused by the walls' wave reflections. The accuracy of the current study's numerical results is ratified by conducting a comparative study using the available data given by other researchers. The study demonstrates that multiple efficiencies occur in the case of the long-wave region as compared to the short-wave region. Additionally, both the shape and magnitude of the efficiency curves are influenced by the slanted design of the device's front wall and the number of trenches.