抄録
We have developed water turbines appropriately for low head open channels to effectively utilize the hydro power energy. To improve the performance of the turbine, it is necessary to determine the free surface flow patterns around the turbine. We introduced the new equipment system and the more precise computational grid of numerical analysis, it was possible to specify more precise flow patterns than old ones. Time-averaged velocity distribution at inner or outer circumference of runner was almost consistent. The flow direction at the second stage outlet had rapidly changed against the mainstream. At the inner circumference of runner at the first stage outlet, the small scale vertical flow toward the same rotational direction of runner occurred. In addition, we investigated the transient flow patterns at outer circumference of the runner.
