Krishnil Ram, Mohammed Faizal, M. Rafiuddin Ahmed and Young-Ho Lee
The Journal of Mechanical Science and Technology, vol. 24, no. 10, pp.2043-2050, 2010

Abstract : A fixed type oscillating water column (OWC) device was designed and tested in a 2-D wave channel. The air chamber was converged to its minimum area at the turbine section to obtain the maximum kinetic energy. The variations in the height of water in the water column and in the static pressure of the air caused by the oscillating waves were studied in detail. The airflow in the entire air chamber was documented with particle image velocimetry measurements. No turbine was installed in the device. The experiments were performed by varying the water depth and the wave frequency. It was found that the air velocities in the turbine chamber during the upward motion of water in the column are always larger than during the downward motion. While the airflow was strong most of the time, very low air velocities were recorded during the transition between the upward and downward flows indicating the need of an airflow regulator before the turbine to get a constant flow rate of air. The well-directed flow obtained at the turbine section can be used to drive a Savonius rotor, which is the most appropriate turbine for rectangular cross-section of the chamber.

Keyword : Wave energy; Oscillating water column; Particle image velocimetry experiments