Aerofoil blade for an axial flow turbomachine
AssigneeALSTOM Technology Ltd
InventorBrian Robert Haller
Life of this patent
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Abstract
An exemplary aerofoil blade for an axial flow turbomachine has a radially inner platform region, a radially outer tip region, an axially forward leading edge, and an axially rearward trailing edge. The aerofoil blade has a pressure surface which is convex in a radial direction, and a suction surface which is concave in the radial direction. The axial width (W) of the aerofoil blade can vary parabolically between maximum axial widths (Wmax) at the platform and tip regions, respectively and a minimum axial width (Wmin) at a position between the platform region and the tip region.
Claims18
An aerofoil blade, comprising:
- a radially inner platform region;
- a radially outer tip region;
- an axially forward leading edge;
- and
- an axially rearward trailing edge which is straight between the platform region and the tip region and oriented radially of an annular path;
- a pressure surface which is convex in a radial direction between the radially inner platform region and the radially outer tip region;
- and
- a suction surface which is concave in the radial direction between the radially inner platform region and the radially outer tip region;
- wherein an axial width (W) of the aerofoil blade, being an axial distance between the leading edge and the straight trailing edge, varies parabolically between maximum axial widths (Wmax) at the platform and tip regions, respectively and a minimum axial width (Wmin) at a position between the platform region and the tip region;
- wherein a K value, being equal to a ratio of a throat dimension (t) to a pitch dimension (p), varies between minimum values (Kmin platform) and (Kmin tip) at the platform region and the tip region respectively, and a maximum value (Kmax) at a position between the platform region and the tip region;
- wherein the minimum K value at the platform region (Kmin platform) is substantially equal to the minimum K value at the tip region (Kmin tip).
An axial flow turbomachine, including a ring of aerofoil blades, each aerofoil blade comprising:
- a radially inner platform region;
- a radially outer tip region;
- an axially forward leading edge;
- an axially rearward trailing edge which is straight between the platform region and the tip region and oriented radially of an annular path;
- a pressure surface which is convex in a radial direction between the radially inner platform region and the radially outer tip region;
- and
- a suction surface which is concave in the radial direction between the radially inner platform region and the radially outer tip region;
- wherein an axial width (W) of the aerofoil blade, being an axial distance between the leading edge and the straight trailing edge, varies parabolically between maximum axial widths (Wmax) at the platform and tip regions, respectively and a minimum axial width (Wmin) at a position between the platform region and the tip region;
- wherein a K value, being equal to a ratio of a throat dimension (t) to a pitch dimension (p), varies between minimum values (Kmin platform) and (Kmin tip) at the platform region and the tip region respectively, and a maximum value (Kmax) at a position between the platform region and the tip region;
- wherein the minimum K value at the platform region (Kmin platform) is substantially equal to the minimum K value at the tip region (Kmin tip).
Dependencies are inferred from the claim text.