Gas turbine nozzle with a flow fence

Patent metadata

Field	Value
Publication number	US-8944774-B2
Application number	US-201213342256-A
Country	US
Kind code	B2
Filing date	Jan 3, 2012
Priority date	Jan 3, 2012
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

The present application provides a turbine nozzle. The turbine nozzle may include an airfoil with a leading edge and a trailing edge and a flow fence extending from the leading edge to the trailing edge.

First claim

I claim:

1. A turbine nozzle, comprising:
an airfoil;
the airfoil comprising a leading edge, a trailing edge, a suction side, and a pressure side; and
a flow fence extending along the suction side comprising:
a first arcuate surface having a first constant radius of curvature extending from the suction side towards a base of the airfoil; and
a second arcuate surface extending from the suction side towards the first arcuate surface, the second arcuate surface having a second constant radius of curvature that is different than the first constant radius of curvature, wherein the first and second arcuate surfaces converge at a line, thereby forming an edge of the flow fence along the line;
wherein:
the flow fence extends from the leading edge to the trailing edge of the airfoil;
the edge of the flow fence formed by the first and second arcuate surfaces is separated from the suction side a first distance at a position between the leading edge and the trailing edge and at a second distance at the leading edge and the trailing edge; and
the first distance is greater than the second distance;

wherein the turbine nozzle is a last stage turbine nozzle.

2. The turbine nozzle of claim 1 , wherein the airfoil extends from a base to a tip and wherein the flow fence is positioned adjacent to the tip.

3. The turbine nozzle of claim 1 , wherein the first and second arcuate surfaces form a substantial V-like cross-sectional shape.

4. The turbine nozzle of claim 1 , wherein the flow fence extends in a substantially linear direction.

5. The turbine nozzle of claim 1 , wherein the flow fence comprises a uniform thickness as measured from a first intersection of the first arcuate surface and the suction side and a second intersection of the second arcuate surface and the suction side.

6. The turbine nozzle of claim 1 , wherein the flow fence comprises a forward leading flow fence, wherein a forward portion of the flow fence positioned near the leading edge of the airfoil extends further from the suction side of the airfoil than a rearward portion of the flow fence positioned near the trailing edge of the airfoil.

7. The turbine nozzle of claim 1 , further comprising a plurality of flow fences.

8. The turbine nozzle of claim 1 , wherein the flow fence comprises a rear leading flow fence, wherein a rearward portion of the flow fence positioned near the trailing edge of the airfoil extends further from the suction side of the airfoil than a forward portion of the flow fence positioned near the leading edge of the airfoil.

9. The turbine nozzle of claim 1 , wherein the flow fence is shaped to reduce flow migration in a flow of hot combustion gases along the airfoil.

10. The turbine nozzle of claim 1 , wherein the flow fence is substantially parallel to a tip of the airfoil.

11. A turbine, comprising:
a plurality of nozzles; and
a plurality of buckets;
the plurality of buckets comprising an airfoil;
the airfoil comprising a suction side, a pressure side, a leading edge, a trailing edge, and a flow fence extending between the leading edge and the trailing edge;
wherein the flow fence comprises:
a first arcuate surface having a constant radius of curvature extending from either the suction side or the pressure side of the airfoil;
a second flat surface extending from either the suction side or the pressure side of the airfoil and converging with the first arcuate surface at a line, such that the first arcuate surface and the second flat surface form an edge of the flow fence along the line of convergence;
wherein the first arcuate surface is positioned closer to a tip of the airfoil than the second flat surface.

12. The turbine of claim 11 , wherein the flow fence extends along the suction side of the airfoil.

13. The turbine of claim 11 , wherein the flow fence extends along the pressure side of the airfoil.

14. The turbine of claim 11 , further comprising a plurality of flow fences.

15. The turbine of claim 11 , wherein the airfoil extends from a base to a tip and wherein the flow fence is positioned adjacent to the tip.

16. The turbine of claim 11 , wherein the flow fence is shaped to reduce flow migration in a flow of hot combustion gases along the airfoil.

17. A turbine nozzle airfoil, comprising:
a leading edge;
a trailing edge,
a pressure side;
a suction side; and
a flow fence extending from along a perimeter of the airfoil, wherein the flow fence comprises:
a first arcuate surface having a first constant radius of curvature extending from the suction side; and
a second arcuate surface extending from the suction side towards the first arcuate surface, the second arcuate surface having a second constant radius of curvature that is different than the first constant radius of curvature, wherein the first and second arcuate surfaces converge at a line, thereby forming an edge of the flow fence along the line of convergence;

wherein the edge of the flow fence formed by the first and second arcuate surfaces is separated from the suction side a first distance at a first position between the leading edge and the trailing edge and is separated from the pressure side a second distance at a second position between the leading edge and the trailing edge, the first distance and the second distance being equal;
the flow fence blends into the leading edge and the trailing edge; and
the turbine nozzle is a last stage turbine nozzle.

Assignees

• Bielek Craig Allen
• Gen Electric

Inventors

• Bielek Craig Allen

Classifications

• F01D5/145 Primary

  Means for influencing boundary layers or secondary circulations (for compressors F04D29/68) · CPC title

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• F01D5/20

  Specially-shaped blade tips to seal space between tips and stator {(F01D5/225 takes precedence)} · CPC title

• F01D9/02

  Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} · CPC title