The Design and Development of an Oscillating Water Turbine

Renewable energy technologies are being developed to solve increasing electrical energy needs. Hydro energy is playing an important role. This paper presents a new concept of hydrokinetic turbine inspired by fish-like motion. The device is based on using an oscillating turbine to extract energy from vortices which are produced from an upstream cylinder. The objectives of this study were: 1) to find out the parameters which affected mechanical power and efficiency, 2) to find out the optimum condition of an oscillating water turbine and 3) to design a full-scale prototype with a cycle-averaged power of 100 W using the similarity methods. The results of the study were as follows: 1) mechanical power and efficiency depended on flow velocity U, diameter of cylinder D, longitudinal distance between cylinder and turbine S, friction torque T and spring stiffness k, 2) the optimum condition which defined as condition of an oscillating turbine with maximum efficiency was at Reynolds number Re = 50645, the ratio of the longitudinal distance between cylinder and turbine S to diameter of cylinder D = 10.4, the reduced friction torque T* = 2.7, the reduced spring stiffness k* = 0.004 and 3) the dimensions of full-scale prototype with a cycle-averaged power of 100 W were presented.