| 摘要 |
<p>Provided is a turbine (1). One of a tip portion of a blade (50) and a portion of a partition plate outer ring (11) corresponding to the tip portion of the blade (50) is provided with a step part (52) having a step face (53) that protrudes toward the other, and the other is provided with seal fins (15) extending out with respect to the step part (52) and forming minute clearance (H) between the step part (52) and the other. The step part (52) facing the seal fins (15) is configured to protrude so that a cavity (C) forming a main vortex and counter vortex being formed by the main vortex are formed on an upstream side of the seal fins (15). The cavity (C) is formed so that an axial width dimension (W) and a radial height dimension (D) satisfy Formula (1) expressed by 0.45‰¤D/W‰¤2.67.</p> |
