Numerical simulation of 0.6m impulse turbine for wave power conversion under different flow conditions

This paper presents the performance analysis of a 0.6m Impulse turbine with fixed guide vanes under uni-directional steady flow and bi-directional sinusoidal flow conditions and comparison with actual experimental results under the former flow condition. The rotor consists of 30 blades with elliptical profile based on optimum design but with a different hub to tip ratio of 0.6. There is a set of symmetric guide vanes on both up-stream and down-stream sections of the rotor, with 26 vanes each. A tip clearance of I turn has been used. The aim of this paper is to predict behavior of impulse turbine under actual sea conditions for wave power conversion using numerical simulation. It was found that under sinusoidal flow conditions, the performance of this turbine is similar to the performance under uni-directional steady flow. This characteristic of Impulse turbine with fixed guide vanes under reciprocating flow conditions gives it an edge over other self-rectifying turbines used for extracting power from sea waves.