US 5,292,230 AGranted

Curvature steam turbine vane airfoil

AssigneeWestinghouse Electric Corp.

InventorWilmott G. Brown

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Abstract

A high performance steam turbine vane having a novel airfoil shape. The pressure surface of the airfoil has a substantially straight region proximate the trailing edge that provides the airfoil with adequate thickness to prevent distortion during forging. The novel shape on the suction surface is such that a first region of the suction surface downstream of the gauging point is essentially straight. Traveling in the upstream direction, the first region is followed by a second region that has a large amount of curvature. The second region is followed by a third region that has a lower curvature than the second region. The third region is followed by a fourth region of constantly increasing curvature that increases to a curvature greater than the curvature of the second region. The fourth region is followed by a fifth region, ending at the leading edge, of essentially constant large curvature that includes the maximum curvature throughout the suction surface.

Claims17

Dependent claims

A steam turbine comprising:

a) a stationary cylinder for containing a steam flow, and a rotor enclosed by said cylinder;
b) a row of blades attached to the periphery of said rotor;
and
c) a row of vanes supported on said cylinder and disposed upstream of said row of blades, each of said vanes having an airfoil portion having leading and trailing edges and forming a suction surface and a pressure surface between said leading and trailing edges, said airfoil portion having a width in the axial direction and having a cross-sectional shape that, in conjunction with said trailing edge of an adjacent one of said vanes in said row, defines a gauging point on said suction surface, said pressure surface having a cross-sectional shape in at least one radial location along said airfoil that has a substantially flat portion that extends upstream from said trailing edge by a distance of at least approximately 40% of said airfoil axial width, said suction surface having a cross-sectional shape in said at least one radial location along said airfoil that has:
(i) a substantially flat first portion forming all of said suction surface that is downstream of said gauging point,
(ii) a curved section portion upstream of said gauging point, said second portion having a first curvature,
(iii) a second curvature along a third portion upstream of said second portion, said second curvature being less than said first curvature, and
(iv) a third curvature along a fourth portion upstream of said third portion and ending at said leading edge, said third curvature being greater than said second curvature.

5 more elements

A row of stationary vanes for a steam turbine, each of said vanes comprising an airfoil portion having leading and trailing edges and forming a suction surface and a pressure surface between said leading and trailing edges, said airfoil portion having a cross-sectional shape that, in conjunction with said trailing edge of an adjacent one of said vanes in said row, defines a gauging point on said suction side, said pressure surface having a cross-sectional shape in at least one radial location along said airfoil that has a substantially flat region proximate said trailing edge and a curved region upstream of said flat region, said flat region extending tangentially from said curved region, said suction surface having a cross-sectional shape in said at least one radial location along said airfoil that has:

a) a substantially flat first portion forming all of said suction surface that is downstream of said gauging point;
b) a first curvature along a second portion of said suction side upstream of said gauging point;
c) a second curvature along a third portion of said suction surface upstream of said second portion, said second curvature being less than said first curvature;
and
d) a third curvature along a fourth portion of said suction surface upstream of said third portion, said third curvature being greater than said second curvature.

2 more elements

Dependencies are inferred from the claim text.