Study on Hydrodynamic Performance of Darrieus-type Cross-flow Water Turbine

抄録

For the purpose of utilization of extremely low-head water power, a small model of Darrieus-type cross-flow water turbine was produced and examined for the effects of channel height and number of blades on turbine performance. Then, time variation in generated torque in a revolution of runner was investigated experimentally and compared with the results of theoretical calculation. Performance tests showed that the best efficiency was obtained by double-blade runner under the narrowest channel height condition. Time variations in measured torque showed strong dissimilarity in their wave pattern and quantitative disagreement in their peak values to the theoretical results obtained under the assumption of a uniform steady relative flow. Theoretical analysis suggests that this difference arises from disregard for the effects of circular motion on a flow around the blade and the unsteady character of flow on a Darrieus blade in the above simple calculation.