Experimental Study of a Radial Turbine Using Pitch-Controlled Guide Vanes for Wave Power Conversion

Manabu Takao,Hiroki Homma,Tae-Whan Kim,Yoshihiro Fujioka,Toshiaki Setoguchi

doi:10.1155/ijrm/2006/17379

Abstract

In order to develop a high-performance radial turbine for wave power conversion, a radial turbine with pitch-controlled guide vanes has been proposed and manufactured in the study. The proposed radial turbine has been investigated experimentally by model testing under steady and sinusoidal flow conditions. Then, the experimental results have been compared with those of the conventional radial turbine for wave power conversion, that is, a radial turbine with fixed guide vanes. As a result, the running characteristics of the proposed radial turbine under steady and sinusoidal flow conditions were clarified and the effect of diffuser setting angle of guide vane on the turbine characteristics was presented. Furthermore, it seems that the proposed radial turbine is much superior to the conventional radial turbine.

Highlights

The performance of radial flow turbines having low rotational speed and low noise level, which can be used for wave power conversion using the oscillating water column (OWC) principle, has been studied by a number of authors (Kaneko et al [1, 2]; McCormick et al [3]; McCormick and Cochran [4]; Veziroglu [5])
The efficiency of impulse blading is higher according to the studies (McCormick et al [3]; McCormick and Cochran [4])
It was clarified by the experiment that the turbine efficiency of impulse blading was not so high because there are large differences between the absolute outlet flow angle and setting angle of the downstream guide vane, and the downstream guide vane does not work as a diffuser (Setoguchi et al [6]; Takao et al [7])

Summary

INTRODUCTION

The performance of radial flow turbines having low rotational speed and low noise level, which can be used for wave power conversion using the oscillating water column (OWC) principle, has been studied by a number of authors (Kaneko et al [1, 2]; McCormick et al [3]; McCormick and Cochran [4]; Veziroglu [5]). It was found that the efficiency of radial turbines using reaction-type rotor blading was extremely low (Kaneko et al [1, 2]). In an attempt to fill this gap, performance characteristics were measured on turbines (508.8 mm rotor diameter) with different guide vane geometries by the authors (Setoguchi et al [6]; Takao et al [7]). It was clarified by the experiment that the turbine efficiency of impulse blading was not so high because there are large differences between the absolute outlet flow angle and setting angle of the downstream guide vane, and the downstream guide vane does not work as a diffuser (Setoguchi et al [6]; Takao et al [7]). The experimental results have been compared with those of a radial turbine with fixed guide vanes

EXPERIMENTAL APPARATUS AND PROCEDURE

Turbine characteristics under steady flow conditions

Turbine characteristics under sinusoidal flow conditions

CONCLUSIONS