A Twin Unidirectional Impulse Turbine for Wave Energy Conversion

Shinya Okuhara,Akiyasu Takami,Toshiaki Setoguchi,Manabu Takao

doi:10.4236/ojfd.2012.24a043

Abstract

A twin unidirectional impulse turbine has been proposed in order to enhance the performance of wave energy plant. This turbine system uses two unidirectional impulse turbines and their flow direction is different each other. However, the effect of guide vane solidity on the turbine characteristics has not been clarified to date. The performances of a uni- directional impulse turbine under steady flow conditions were investigated experimentally by using a wind tunnel with large piston/cylinder in this study. Then, mean efficiency of the twin impulse turbine in bidirectional airflow has been estimated by a quasi-steady analysis using experimental results in order to investigate the effect of guide vane solidity on the performance.

Highlights

In recent years, the power take-off mechanism in the oscillating water column (OWC) based wave energy plant has generally comprised of a bidirectional turbine, such as Wells turbine [1]
Mean efficiency of the twin impulse turbine in bidirectional airflow has been estimated by a quasi-steady analysis using experimental results in order to investigate the effect of guide vane solidity on the performance
The power take-off mechanism in the oscillating water column (OWC) based wave energy plant has generally comprised of a bidirectional turbine, such as Wells turbine [1]

Summary

Introduction

The power take-off mechanism in the oscillating water column (OWC) based wave energy plant has generally comprised of a bidirectional turbine, such as Wells turbine [1]. An alternative to the use of a bidirectional turbine is an approach utilizing a unidirectional turbine with two or four valves that act to force air into the turbine in the same direction during exhalation or inhalation from air chamber. It has had success in navigational buoys for 30 years, the principle was not adopted in larger plant. The objective of this paper is to investigate the effect of guide vane solidity on the performance of twin unidirectional impulse turbine for wave energy conversion, in order to clarify the suitable geometry of the turbine. The performance is estimated by a quasi-steady analysis using experimental results in the study

Experimental Setup and Procedure

Experimental Results

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Conclusions