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 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 rotor blade includes a blade portion that extends in a spanwise direction from a hub portion to a tip portion and has a pressure-side surface and a suction-side surface, a blade portion is formed by profiles with airfoil shapes stacked in the spanwise direction, and a stacking line connecting gravity centers of the profiles at each spanwise position is a straight line parallel to a radial direction at a part from the hub portion to an outer end of a secondary flow region in a vicinity of the hub portion, and is a curved line, along which a distance measured from the straight line parallel to the radial direction toward a side of the suction-side surface gradually increases toward the tip portion, at a part from the outer end of the secondary flow region to the tip portion.

Abstract: An airfoil of an axial flow machine includes an airfoil part that has a suction surface and a pressure surface, an endwall as a shroud or a platform, and a fillet that is provided along a connecting portion between the airfoil part and the endwall. The fillet includes a first curved surface formed at least on a leading edge side and a trailing edge side in the airfoil part on the suction surface side and a second curved surface formed in a portion other than a portion where the first curved surface is formed. The second curved surface has a smaller curvature radius than the first curved 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 rotor blade of an axial-flow fluid machine capable of maintaining an effect of reducing a bending stress acting on a blade portion and reducing a secondary flow loss in the vicinity of a hub-side end wall. A rotor blade includes a blade portion that extends in a spanwise direction from a hub portion to a tip portion and has a pressure-side surface and a suction-side surface, a blade portion is formed by profiles with airfoil shapes stacked in the spanwise direction, and a stacking line connecting gravity centers of the profiles at each spanwise position is a straight line parallel to a radial direction at a part from the hub portion to an outer end of a secondary flow region in a vicinity of the hub portion, and is a curved line, along which a distance measured from the straight line parallel to the radial direction toward a side of the suction-side surface gradually increases toward the tip portion, at a part from the outer end of the secondary flow region to the tip portion.

Abstract: Provided is a blade on which a secondary flow loss is reduced without changing aerodynamic design of a base blade.

Abstract: An airfoil of an axial flow machine includes an airfoil part that has a suction surface and a pressure surface, an endwall as a shroud or a platform, and a fillet that is provided along a connecting portion between the airfoil part and the endwall. The fillet includes a first curved surface formed at least on a leading edge side and a trailing edge side in the airfoil part on the suction surface side and a second curved surface formed in a portion other than a portion where the first curved surface is formed. The second curved surface has a smaller curvature radius than the first curved surface.

Abstract: A turbine blade has a profile including a blade suction side line, a blade pressure side line, and a blade trailing edge positioned between the rear ends of the blade suction side and pressure sidelines. The blade trailing edge of the profile is formed by connecting a pressure side arc-like curve having a constant radius of curvature and extending from the rear end of the blade pressure side line toward the camber line of the profile, and a suction side line portion which extends from the rear end of the blade suction side line toward the camber line while passing through a region closer to the camber line than a symmetric curve portion which is line-symmetric to the pressure side arc-like curve with respect to the camber line. The suction side line portion is represented by curves constituting ellipses which constitute ellipses, and a straight line.

Abstract: An axial turbo machine includes: a plurality of blades that constitutes a moving blade row or a stationary blade row; an end wall 1 to which the plurality of blades is fixed and which forms a channel of a fluid together with the blades; and at least one concave portion that is locally formed in a region located between the adjacent blades or on the upstream side of a front edge of the blade on a surface of the end wall and that controls a secondary flow of the fluid.

Abstract: A turbine blade has a profile including a blade suction side line, a blade pressure side line, and a blade trailing edge formed by a curve connecting the rear ends of the blade suction side and pressure side lines to each other, wherein the curve forming the blade trailing edge of the profile is formed by connecting a pressure side curve portion which has an arc shape having a constant radius of curvature and extending from the rear end of the blade pressure side line toward the camber line of the profile, and a suction side curve portion which extends from the rear end of the blade suction side line toward the camber line while passing through a region closer to the camber line than a symmetric curve portion which is line-symmetric to the pressure side curve portion with respect to the camber line.

Abstract: A turbine blade has a profile including a blade suction side line, a blade pressure side line, and a blade trailing edge positioned between the rear ends of the blade suction side and pressure sidelines. The blade trailing edge of the profile is formed by connecting a pressure side arc-like curve having a constant radius of curvature and extending from the rear end of the blade pressure side line toward the camber line of the profile, and a suction side line portion which extends from the rear end of the blade suction side line toward the camber line while passing through a region closer to the camber line than a symmetric curve portion which is line-symmetric to the pressure side arc-like curve with respect to the camber line. The suction side line portion is represented by curves constituting ellipses which constitute ellipses, and a straight line.

Abstract: A turbine blade has a profile including a blade suction side line, a blade pressure side line, and a blade trailing edge formed by a curve connecting the rear ends of the blade suction side and pressure side lines to each other, wherein the curve forming the blade trailing edge of the profile is formed by connecting a pressure side curve portion which has an arc shape having a constant radius of curvature and extending from the rear end of the blade pressure side line toward the camber line of the profile, and a suction side curve portion which extends from the rear end of the blade suction side line toward the camber line while passing through a region closer to the camber line than a symmetric curve portion which is line-symmetric to the pressure side curve portion with respect to the camber line.