Ihi Corporation

Daisuke Nishii

Masaaki Hamabe

Juo Furukawa

Yasuhiro Okamura

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. The modified trailing-edge curve includes a portion of the trailing-edge curve of the base airfoil in the spanwise region where the elevated portion is provided, the portion being closer to the pressure side or the suction side than the trailing edge, and an elevated portion curve. The elevated portion curve includes a concave front-side curve and a convex rear-side curve.

Method for modifying blades of fan, compressor, and turbine of axial flow type, and blades obtained by the modification

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.

Secondary flow suppression structure

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.

Method for designing vane of fan, compressor and turbine of axial flow type, and vane obtained by the designing

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.

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Tokyo, Japan

Daisuke Nishii