Influence of distance from water surface of a horizontally installed Savonius turbine in a rectangular open channel on turbine performance

The aim of this investigation is to develop a nano-hydro turbine that can effectively utilize the wasted hydraulic energy in infrastructure such as agricultural and industrial canals and irrigation waterways. Up to this time, the utilization of such a small hydropower has not progressed owing to economic reasons. Therefore, we focus on the Savonius type, which has the advantages of low manufacturing cost and excellent maintainability because of its simple structure. Conventionally, the Savonius type has been developed and researched as a vertical axis wind turbine. In order to effectively utilize the water surface flow, which is particular to open channels, we place the turbine runner perpendicular to the water flow and horizontally on the channel bottom. In the present study, we experimentally investigated the effect of the parameters for the turbine installation and its operation, namely distance between a runner and the water surface and the rotation direction of the runner, on the performance at each water level. As a result, it was found that the suitable installation depth differs depending on the rotation direction of the turbine.