Segmented turbine blade squealer tip and cooling method
AssigneeSiemens Aktiengesellschaft
InventorsChing-Pang Lee, Kok-Mun Tham, Gm Salam Azad
Life of this patent
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Abstract
Gas turbine engine blade squealer tips incorporate cooling slots formed in the suction side rail downstream of the leading edge for directing cooling gas flow along an inside edge of the squealer tip pressure side rail. Some embodiments incorporate a tip fin on the suction side rail proximal a cooling slot. Segmented suction side rail embodiments abrade opposing turbine casing abradable surfaces prior to potential contact with the pressure side rail, reducing likelihood of pressure side rail friction heating. During turbine engine operation cooler pressure side rails reduce likelihood of squealer tip erosion.
Claims17
A gas turbine engine blade squealer tip, comprising:
- an airfoil planform tip plate having along its outer periphery downstream from its leading edge and upstream from its trailing edge opposed and laterally separated projecting concave pressure and convex suction rails respectively having inner and outer faces;
- an enclosed tip cavity defined between the tip plate and respective inner faces of the pressure and suction rails from the leading to trailing edges;
- at least one slot formed through respective inner and outer faces of the suction rail downstream of the leading edge, the slot in communication with the tip cavity and oriented for directing cooling air flow there through and downstream along the pressure rail inner face;
- and
- a first tip fin projecting from the tip plate, having an upstream portion proximal the suction rail, a downstream portion oriented in the tip cavity and an outer face defining an upstream side of a first slot formed in the suction rail, the first tip fin oriented for directing cooling air flow through the first slot and downstream along the pressure rail inner face.
A method for manufacturing a gas turbine engine blade squealer tip pressure side rail, comprising:
- providing a turbine blade with an airfoil planform tip plate having along its outer periphery downstream from its leading edge and upstream from its trailing edge opposed and laterally separated projecting concave pressure and convex suction rails respectively having inner and outer faces and an enclosed tip cavity defined between the tip plate and respective inner faces of the pressure and suction rails from the leading to trailing edges;
- determining a location for at least one slot in the blade tip through respective inner and outer faces of the suction rail downstream of the leading, with the slot in communication with the tip cavity and oriented for directing cooling air flow there through and downstream along the pressure rail inner face;
- forming the slot in the blade tip at said determined location;
- and
- forming a first tip fin projecting from the tip plate, having an upstream portion proximal the suction rail, a downstream portion oriented in the tip cavity and an outer face defining an upstream side of a first slot formed in the suction rail, the first tip fin oriented for directing cooling air flow through the first slot and downstream along the pressure rail inner face.
A gas turbine engine, comprising:
- a rotor having blades radially projecting therefrom;
- each blade having a squealer tip including:
- an airfoil planform tip plate having along its outer periphery downstream from its leading edge and upstream from its trailing edge opposed and laterally separated projecting concave pressure and convex suction rails respectively having inner and outer faces;
- an enclosed tip cavity defined between the tip plate and respective inner faces of the pressure and suction rails from the leading to trailing edges;
- and
- at least one slot formed through respective inner and outer faces of the pressure rail downstream of the leading edge, each respective slot in communication with the tip cavity and oriented for directing cooling air flow there through and downstream along the pressure rail inner face;
- and a first tip fin projecting from the tip plate, having an upstream portion proximal the suction rail, a downstream portion oriented in the tip cavity and an outer face defining an upstream side of a first slot formed in the suction rail, the first tip fin oriented for directing cooling air flow through the first slot and downstream along the pressure rail inner face.
Dependencies are inferred from the claim text.