Abstract
Wells turbine can rotate in the same direction even in the reciprocating air flow produced by the oscillating water column inside of the air chamber which is fixed at the sea surface. It means that Wells turbines have self-rectifying characteristics and make the total wave power system simple.
Although the Wells turbine is simple, the turbine produces the complicated flow field with the distinctive blades. In order to understand the flow, we visualized it. The performance tests were done in the wind tunnel, and the flow patern on Wells turbine blades were visualized by using the oil film method in the water tunnel. The influence of sweep angle was explained by these experiments.
