A case study on tandem configured oscillating foils in shallow water

Previous research on the oscillating-foil turbine system has demonstrated its great potential for energy extraction. However, not much is known about the interaction of this device with its working environment. To determine the performance and environmental impact of an oscillating-foil turbine in shallow water, a case study have been conducted which was made of the dual oscillating energy extraction foils system with a tandem configuration which operates at two different water depths: i.e., D = 5c and D = 10c. The performance and the environmental effects of the device were compared between shallow-water and deep-water cases. The results show a 10% efficiency loss in the D = 5c case compared with that of the deep water case, because of the interaction between the oscillating-foils and the seabed. It is also observed that the foil vortices dissipation rate of the D = 5c case is 13% less than that of the deep-water case due to the free-surface effect. The water level also rises 23% around the oscillating-foils location of the D = 5c case because of the blockage effect of the device.