Influence of harbour wall on pressure variation in an oscillating water column

In the midst of a variety of wave energy converters (WECs), the oscillating water column (OWC) device that exploits ocean waves for its energy is an important class. It is a partially submerged structure with an opening to the sea below the water line that traps the air above the water column. Owing to the wave motion, the rise and fall of water level in a closed chamber pump the air thus causing its oscillation to drive a turbine coupled to electric generators. The objective of the present study is to analyse the influence of harbour walls on the pressure variation between the inside and front of the lip wall of a bottom mounted OWC. In contemplation of enumerating the influence of the harbour walls, a two-dimensional physical model study was conducted with a model scale of 1:20 in a 72.5 m long, 2 m wide and 2.5 m deep wave flume. The study was carried out with different configurations of harbour walls by changing its projecting length to examine the response of OWC. The dimensions of OWC have been chosen in such a way that the device can absorb more energy for a particular relative water depth (d/L). The model was exposed to the action of regular waves in order to evaluate the hydrodynamic performance characteristics of the device mainly the effect of the harbour walls. The details of test set-up, testing facility, parameters of models, harbour wall configurations, test procedure, analysis of results and discussion are reported in this paper.