Modelling of unsteady effects for a direct drive tidal energy converter

In this study, unsteady effects on an oscillating profile type tidal energy device are being investigated. A numerical method has been developed, based on vortex shedding from the trailing edge, in order to perform the investigations. The method is applied to a test case and the influence of the reversal period ratio, angle of attack and the velocity ratio on the unsteady effects has been systematically investigated. It has been concluded that for the moderate angle of attack the efficiency of the device will not be significantly affected while changes in the reversal period ratio and the velocity ratio play an important role in the efficiency of the device.