To solve the problems wherein, it is anticipated that in a runner with both a straightening blade and an intermediate blade short in blade length added to a normal runner, improved efficiency in an undesigned point is achieved in comparison with the other existing runner, however, it is still insufficient for reducing a hydraulic loss.
The runner for a Francis hydraulic machine includes: a runner crown 2; a runner band 3; runner blades 4; the straightening blades 6 arranged along a flow passage between the runner crown 2 and the runner band 3 and intersecting with each runner blade 4; and short runner blades 5a, 5b shorter in blade length than the runner blades 4 and arranged in a flow passage formed by the runner crown, the straightening blades 6, and the adjacent blades 4. B1 represents a distance between the runner crown on the peripheral side of the runner and the straightening blade, L1 represents a distance between the runner blades in a runner blade inlet on a side formed by the runner crown and the straightening blade, and L11 represents a distance from the pressure surface of the runner blade to the vacuum surface of the short runner blade. In this case, the distance B1 between the runner crown 2 and the straightening blade 6 is set to satisfy formula (1): 0.8L11B11.2L11.
NAKAMURA KAZUYUKI
NAKAMURA TAKANORI
SHINOHARA AKIRA
TEZUKA KOTARO
Yoshiaki Inomata
Hiroko Inomata
Hiroshi Shimura