Effect of Stall Fence on the Performance of an Axial Turbine for Wave Energy Conversion

Abstract

Wells turbine is one type of axial turbine exclusively used for wave energy conversion in Oscillating Water Column type wave energy conversion device. It is a bi-directional turbine which can rotate in one direction irrespective of the direction of airflow. One of the main disadvantages of this turbine is the stall phenomenon, where the torque, as well as efficiency, drops drastically at a particular angle of attack. The postponement of stall can be achieved by installing fences along the chord of the blade at a distance from the hub. In the present work, a numerical analysis of Wells turbine with the stall fence is carried out using commercial CFD tool ANSYS. The performance characteristics of the turbine are investigated for different number of stall fences at different distances along the span of the blade. A detail flow analysis is presented to explain the effect of the stall fence on this particular turbine.