二重反転形小型ハイドロタービンのスペーサの軸方向距離が性能に及ぼす影響

抄録

In order to effectively utilize unused hydraulic resources in irrigation channels, and simple water supply systems, it is essential to improve the performance and reduce the size of small hydroturbines. In this study, we adopted a contra rotating rotors that efficiently recovers energy by using two rotors, with the aim of achieving both high performance and compactness in a small hydroturbine. In previous studies, the front and rear rotors of this test turbine are connected by a spacer with four spokes, but the optimal axial distance of the spacer has not yet been clarified. Therefore, we conducted a numerical analysis to investigate the effect of the axial distance of the spacer on the performance of the test turbine (D50 model) with a diameter of 50 mm. In this paper, we focus on the performance characteristics and internal flow of four models with different axial distances of the spacer, and report the results.