HYDRODYNAMIC CHARACTERISTICS OF AN OSCILLATING WATER COLUMN DEVICE

We consider a wave energy device consisting of a thin vertical surface -piercing barrier next to a vertical wall in finite depth water. Power is extracted due to a normally incident wave forcing the free surface of the fluid between the barrier and the wall to oscillate, in turn p umping the volume of air above the free surface through a uni-directio nal turbine housed at the opening of the device. Under the assumptions of linear water wave theory, the important hydrodynamic properties ar e expressible in terms of integral quantities of functions proportiona l to the fluid velocity under the barrier. These functions each satisf y integral equations, the solutions of which are approximated very acc urately and efficiently using a Galerkin method as described in Porter and Evans [Porter, R. & Evans, D. V., Complementary approximations to wave scattering by vertical barriers. J. fluid Mech., 294 (1995) 155- 80].