抄録
The power performance of a waterfall crossflow hydraulic turbine was numerically investigated by solving the unsteady Reynolds averaged Navier–Stokes equations combined with the volume-of-fluid method. In this study, characteristic parameters such as the tip-speed ratio, offset distance, and number of blades were investigated numerically to improve the power performance of the hydraulic turbine. Two optimum conditions were obtained in this study: one was the operation at mid-offset distances of 0.35–0.43, and the other was that at a large offset distance of 0.48, which is the condition of flow impact near the blade edge. The former operation yielded a peak efficiency at a tip-speed ratio of approximately 0.7. The peak value slightly increased with an increase in the number of blades. However, the latter operation resulted in a peak efficiency at a lower tip-speed ratio of 0.6, and it sharply increased with an in-crease in the number of blades. This latter feature could be caused by the operation at the optimum inlet angle to the blade at an offset distance of 0.48, where the lift force contribution was clearly observed in the flow field.
https://ror.org/0244rem06 
