Numerical and experimental study on 30kW-class impulse turbine for wave energy conversion

Abstract

The present study deals with the design of the optimum impulse turbine for 30kW-class Oscillating Water Column (OWC) wave energy converter. The diameter of turbine was determined to be 0.8m through conceptual design process. For the basic design, the numerical analysis tool was established based on the commercial CFD code, FLUENT. The conventional-type impulse turbine was designed by optimizing the design parameters such as number of blade, angle of guide vane, hub ratio and tip clearance. The numerical results was validated with experiment performed using a specially-built reciprocating flow generator to simulate the wave movement inside OWC. The ring-type impulse turbine for better efficiency was then proposed in order to reduce the vortex roll-up near the tip of rotor blade. The depth of penetration, thickness and length of ring were key parameters investigated in the present study. It was found that a ring-type turbine shows approximately 7% higher in peak efficiency than that of a conventional-type turbine. Copyright ？ 2018 by the International Society of Offshore and Polar Engineers (ISOPE)