Experimental study on the overall performance of a model OWC system under the free-spinning mode in irregular waves

The evaluation of the overall performance evaluation is important to the design of an oscillating water column (OWC) device. A generic OWC model was tested experimentally in a wave flume, which employed a real impulse turbine model to be connected with the air chamber. The performances of the OWC model under the free-spinning mode of the turbine model in irregular wave scenarios were analyzed. Effects of the electronic resistance acting as external loads to the drive train on the primarystage, secondary-stage, and overall performances were studied. The peak efficiencies under the freespinning and forced-spinning modes were compared. Furthermore, an integrated numerical model was employed to compare the OWC performances under irregular and regular wave scenarios with same incident powers. The numerical predictions indicate that the OWC model obtains the peak efficiencies at different wave period values for two wave scenario types.