A review of impulse turbines for wave energy conversion

Oscillating Water Column based wave energy plants convert wave energy into low pressure pnuematic power in the form of bi-directional air flows. Air turbines which are capable of rotating uni-directionally in bi-directional air flow, otherwise also known as self-rectifying turbines, are used to extract mechanical shaft power which is further converted into electrical power by a generator. This paper reviews the state of the art in self-rectifying impulse air turbines. New results on optimum parameters for the fixed-guide-vane impulse turbine are also presented. Starting characteristics and conversion efficiencies of two types of impulse turbines are compared with the well known Wells turbine.