EXPERIMENTAL STUDY OF WAVE HEIGHT EFFECT ON EFFICEINCY OF AN OFFSHORE FIXED FLOATING OWC

Renewable energy is one the most interesting marine issues researchers have studied in the last two decades. Considering fossil energy limited resources and their pollutant nature, it is indispensable to find a solution for world future energy demand. Among different kinds of marine renewable energies, wave energy is one of the best resources as it includes higher energy density. Oscillating Water Column is a wave energy converter consisting of a chamber which can be built as a fixed shore or nearshore device or can be a floating one.The mechanism of OWC working includes wave induced water fluctuation inside a chamber followed by air compressing or decompressing. The pressurized air passesthrough a vent or nozzle to drive a turbine installed to the chamber. Although there are a lot of studies on OWCs, they are not fully commercialized due to their sophisticated hydrodynamic behavior. There are a lot of studies conducted on OWCs. A huge part of that is devoted to num erical studies which themselves can be classified into researches based on potential theory [1,2] or studies performed according to Navier-Stokes equation [3,4]. Experimental approach is another method which is undoubtedly crucial in order toreach commercializing stage of OWCs. Contrary to shore based or nearshore OWCs fixed at the sea bottom[5], [6], there are limited experimental tests for floating offshoreOWCs. Offshore OWCs has the merit of being exposed to higher wave energy. Moreover, wave energy dissipation takes place more extremely at shallow water region so that70% of energy may be dissipated through seabed friction and wave breaking [7]. Hence, in this paper efficiency of a fixed floating offshore OWC is investigated. As most of the previous studies focused on wave period and Power Take Off (PTO) damping, this paper is devoted to wave height effect on OWC efficiency