リングランナを用いた小型プロペラ水車の性能評価

抄録

This study aims to elucidate the small propeller turbine performance by attaching the outer ring on the runner vane periphery. The unique shape runner has some advantages; suppressing tip leakage, improving turbine efficiency, and strengthening the runner blade. To get better turbine performance with low cost and short time, the authors try to make the runner for small propeller turbine by additive manufacturing technology. It is almost no limit of shapes of runner and guide vane changed the runner blade shape. So, the authors investigate the turbine performance for five types of ring runner by CFD analysis. As a result, the turbine with a full-width outer ring and airfoil blade shows the best turbine efficiency of 80%. It clarifies the outer ring’s role for the turbine performance and the turbine efficiency of each model. The differential pressure between pressure and suction side of the runner blade becomes maximum in the full ring model. The full width ring runner is effective to surpress the tip leakage and improve the turbine performance.