Abstract: A secondary flow suppression structure includes: a turbine rotor blade including an outer shroud; a turbine stator vane located rearward of the turbine rotor blade and including an outer band; a seal surface facing the outer shroud at a radial outside of the outer shroud; a fin projecting from the outer shroud toward the seal surface; and a cavity formed between the seal surface and the turbine stator vane, formed in an annular shape extending in a circumferential direction, and provided with an opening portion opening radially inward on a virtual surface of the seal surface extending rearward. A front end of the outer band is positioned at the same height as the virtual surface in a radial direction, or positioned radially inward of the virtual surface.

Abstract: Provided are a method for designing a vane, which can reduce peaks of secondary flow losses appearing locally in secondary flow regions and a vane obtained by the designing. The method for designing a vane includes: a step of determining a base vane formed by stacking profiles having airfoil shapes in a spanwise direction along a stacking line which is configured as a smooth curved line having no inflection point or a straight line; and a step of changing the stacking line of the base vane to a smooth wavy curved line which waves in an axial direction of a fan, a compressor or a turbine and has no elbows.

Abstract: Provided is a blade capable of optimizing an outflow angle in substantially the entire hub region and tip region, particularly in a blade-end-side hub region and a blade-end-side tip region. The blade includes: a base blade part; a suction-side elevated portion provided on a suction surface near a trailing edge in at least one of the blade-end-side tip region and the blade-end-side hub region of the base blade part; and a pressure-side elevated portion provided on a pressure surface near the trailing edge in at least one of a midspan-side tip region and a midspan-side hub region of the base blade part. An airfoil at each spanwise position where the elevated portion is provided is such that a trailing-edge curve of a base airfoil is changed to a modified trailing-edge curve.

Abstract: A stator vane segment includes: a plurality of airfoil portions; and one outer band and one inner band joined to a tip portion and a hub portion of each airfoil portion. Each airfoil portion is formed by stacking airfoil profiles in a spanwise direction from the hub portion to the tip portion. Each profile includes a leading edge, a trailing edge, a pressure surface, and a suction surface, in a stacking line connecting respective trailing edges of the profiles at spanwise positions. A portion from the tip portion to a predetermined position is a straight line in a radial direction. A portion from the predetermined position to the hub portion is shifted from the pressure surface toward the suction surface in a circumferential direction from the straight line parallel to the radial direction. An amount of the shift monotonically increases from the predetermined position to the hub portion.

Abstract: A secondary flow suppression structure includes: a turbine rotor blade including an outer shroud; a turbine stator vane located rearward of the turbine rotor blade and including an outer band; a seal surface facing the outer shroud at a radial outside of the outer shroud; a fin projecting from the outer shroud toward the seal surface; and a cavity formed between the seal surface and the turbine stator vane, formed in an annular shape extending in a circumferential direction, and provided with an opening portion opening radially inward on a virtual surface of the seal surface extending rearward. A front end of the outer band is positioned at the same height as the virtual surface in a radial direction, or positioned radially inward of the virtual surface.

Abstract: A stator vane segment includes: a plurality of airfoil portions; and one outer band and one inner band joined to a tip portion and a hub portion of each airfoil portion. Each airfoil portion is formed by stacking airfoil profiles in a spanwise direction from the hub portion to the tip portion. Each profile includes a leading edge, a trailing edge, a pressure surface, and a suction surface, in a stacking line connecting respective trailing edges of the profiles at spanwise positions. A portion from the tip portion to a predetermined position is a straight line in a radial direction. A portion from the predetermined position to the hub portion is shifted from the pressure surface toward the suction surface in a circumferential direction from the straight line parallel to the radial direction. An amount of the shift monotonically increases from the predetermined position to the hub portion.

Abstract: Provided are a method for designing a vane, which can reduce peaks of secondary flow losses appearing locally in secondary flow regions and a vane obtained by the designing. The method for designing a vane includes: a step of determining a base vane formed by stacking profiles having airfoil shapes in a spanwise direction along a stacking line which is configured as a smooth curved line having no inflection point or a straight line; and a step of changing the stacking line of the base vane to a smooth wavy curved line which waves in an axial direction of a fan, a compressor or a turbine and has no elbows.