| 摘要 |
<p>When the trigonometric function of the phase lag of the hydraulic excitation of the runner vanes (2c), which varies in accordance with the combination of the number of runner vanes (R) and the number of guide vanes (G) of a high head pump/turbine is denoted by cos( theta Rn), the thickness of the crown (2a) along a circle of a diameter at a mid point of the diameter (Do) of the outermost periphery of the runner is denoted by tMC, the thickness of the band (2b) is denoted by tMB, the mean thickness of the crown at the outer peripheral portion of the runner is denoted by tC, the mean thickness of the band is denoted by tB, and the rigidity ratio of the crown and band to the runner vane is denoted by KR taking the rigidity of the runner vane as a reference, the moment coefficient CM0 which is a function of cos( theta Rn) and the rigidity ratio KR is selected to be less than 0.5 in accordance with the value of cos( theta Rn), and relations tC/tMC >/= l and tB/tMB >/= l are selected when the value of cos( theta Rn) is positive and relations tC/tMC </= l and tB/tMB </= l are selected when the value of cos( theta Rn) is negative. <IMAGE> <IMAGE></p> |
