ガイド壁と円筒状キャビティを有するクロスフロー水車において回転軸径が水車性能に与える影響

抄録

Many small hydropower stations, which is run-off river type, use a cross-flow turbine because of its excellent partial load characteristics with low manufacturing cost. So far, there have been various studies to improve the turbine performance. The authors have been developing a new shape cross-flow turbine with a cylindrical cavity and a guide wall to enhance the performance and make the turbine small. This study focuses on the interaction of the runner internal flow named cross-flow to a runner shaft. Of course, the design process of the shaft diameter carefully considers mechanical strength performance based on structural mechanics and strength of materials. On the other hand, there is little knowledge of the hydrodynamic interaction between the cross-flow and the shaft. So, the authors investigate the influence of the runner shaft diameter on the hydrodynamic performance. As a result, turbine performance deteriorates as the runner shaft diameter increases and the larger opening of a guide vane. The runner torque decreases by the interaction.