| 摘要 |
PURPOSE:To reduce a loss at the tip of a stationary blade and to improve stage effect, by making the tip of the external circumferential side of a stationary blade into a structure through which its blade inlet angle is increased in the opposite direction of a rotation of a moving blade and its attack angle is reduced, in a multi-stage axial flow turbine. CONSTITUTION:A stationary blade 1 is made into a structure through which a blade inlet angle betam from a blade root of an inner circle 2b side to a C-C cross section part which is kept at a distance of h from an external circle 2a is made to about coincide with that of a center axis 11 of a turbine and the inlet blade angle betam from the C-C cross section part up to a B-B cross section part of the tip of the external circumferential side which touches the external circle 2a is increased in the opposite direction of a rotation of a moving blade. A blade inlet angle betam, t at the B-B cross section of the external circumference is set to more than 20 deg.. In addition to the above, when a distance from a trailing edge 5b of the preceding moving blade up to a leading edge 1a of the stationary blade is L, a gradual increase range h of the blade inlet angle is set so as to give h<0.5L. In this manner, a loss at the tip of the stationary blade is reduced and stage effect can be improved. |
