The Contribution of L-shaped front wall in the improvement of the oscillating water column wave energy converter performance

Abstract In order to diminish the energy resources, the attempts to convert wave energy into an electrical one and to develop the existing devices are very important issues. Our study investigated numerically the effect of replacing simple front wall with L-shaped front wall on the oscillating water column (OWC) wave energy converter performance. L-Shaped front wall with an entrance duct extended in wave counter flow direction was studied under various regular waves. Two-dimensional numerical wave tank was validated with pervious experimental works. Then, it was used to examine the influence of entrance duct length on the air pressure and the free surface vertical motion in the chamber. The results showed that the type of L-Shaped front wall reduced the air pressure because of the generation of vortices. Despite that, the performance was improved in the case of short entrance duct length in high wave lengths. This improvement was due to the reduction in the shift angle between the pressure curve and free surface vertical velocity curve. In the present work, it was concluded that the counter flow L-shaped front wall with small entrance duct length with respect to the chamber length could improve the average output power in long waves.