FRANCIS-TYPE TURBINE RUNNER AND FRANCIS-TYPE TURBINE

摘要

According to an embodiment, the vane 13 has a thick root portion 16P formed on the band 12 side of a pressure surface to be joined to the band 12, with a thickness of the thick root portion 16P being gradually increased toward the band 12, and a thick root portion 16N formed on the band 12 side of a negative pressure surface to be joined to the band 12, with a thickness of the thick root portion 16N being gradually increased toward the band 12. The outlet end 15 has a first curved portion 151 and a second curved portion 152. An extreme point 15B forming a bottom end of the second curved portion 152 is positioned closer to the band 12 than an end of the thick root portion 16P, 16N on the crown 11 side.