Turbine For Wave Energy Conversion Research Articles

Comparison of Performances of Turbines for Wave Power Conversion.

A number of self-rectifying air turbines for wave power conversion have been proposed over the last decade. However, the comparison of their characteristics has not been made so far. This paper reviews the present state of the art of the self-rectifying air turbines for wave energy conversion, and shows the comparison of the performances of the turbines. In order to clarify the turbine characteristics, the experimental investigations have been performed under steady flow conditions. And then, the starting and running characteristics in irregular flow have been obtained by a computer simulation. As a result, it is clarified that the impulse type turbine is superior to the Wells type turbine in the overall characteristics.

Studies on a Wells Turbine for Wave Energy Conversion. (Improvement of Performance by the Use of Porous Fences).

In order to improve the performance of a Wells turbine, the porous fences have been equipped on the hub wall upstrem and downstream of the rotor. The effects of the gap between the porous fence and rotor, porosity and height of the porous fence have been investigated by model testing. The results have been compared with those of the case without porous fences. As a result, it is found that the starting characteristics are improved by the porous fences. Furthermore most of the configurations tested have shown improvements in the operation range primarily by postponement of stall. A suitable choice of design parameters for the turbine has been suggested.

35 自己可変ピッチタンデム案内羽根を有する波力発電用衝動タービンの研究

As a self-rectifying turbine for wave energy conversion, the new versions of impulse-turbine with self-pitch-controlled tandem guide vane are proposed. These include (1) variable-pitch flat-plate type and (2) variable-pitch splitter type. In order to examine the unsteady characteristics of the turbines, the experimental investigations have been made by a special turbine equipment and flow visualization using smoke wire method. The result shows that a high-efficiency impulse turbine can be developed through the use of the splitter. It is found that, in this case, the upstream guide vanes act as a slotted nozzle blade row and the downstream vanes as a tandem diffuser blade row by changing the pitch angle of the splitter automatically in a reciprocating flow