Two portion cooling passage for airfoil

Patent metadata

Field	Value
Publication number	US-2019211685-A1
Application number	US-201815862932-A
Country	US
Kind code	A1
Filing date	Jan 5, 2018
Priority date	Jan 5, 2018
Publication date	Jul 11, 2019
Grant date	—

Abstract

A turbine airfoil includes a body having an airfoil wall, and a coolant chamber within the body. A plurality of cooling passages are within the airfoil wall, each cooling passage includes: a first portion extending from a first point on an exterior surface of the airfoil wall to the coolant chamber, and a second portion extending from a second point on the exterior surface of the airfoil wall distal from the first point to intersect a mid-portion of the first portion. A cap element closes the first portion at the first point but leaving the second portion open. Each cooling passage has a single inlet in fluid communication with the coolant chamber and a single outlet at the second point of the second portion.

First claim

What is claimed is:

1 . A turbine airfoil, comprising:
a body having an airfoil wall; a coolant chamber within the body; and a plurality of cooling passages within the airfoil wall, each cooling passage including:
a first portion extending from a first point on an exterior surface of the airfoil wall to the coolant chamber,
a second portion extending from a second point on the exterior surface of the airfoil wall distal from the first point to intersect a mid-portion of the first portion, and
a cap element closing the first portion at the first point but leaving the second portion open,
wherein each cooling passage has a single inlet in fluid communication with the coolant chamber and a single outlet at the second point of the second portion.

2 . The turbine airfoil of claim 1 , wherein the second point of the second portion includes a diffuser opening in an axially downstream direction from the leading edge.

3 . The turbine airfoil of claim 2 , wherein the second portion diverges relative to the exterior surface and an interior surface of the airfoil wall along a length thereof from the mid-portion of the first portion to the second point.

4 . The turbine airfoil of claim 2 , wherein the second portion diverges radially at angles between 0° and approximately 20° relative to a length of the body along a length of the second portion from the mid-portion of the first portion to the second point.

5 . The turbine airfoil of claim 1 , wherein the second portion crosses the mid-portion of the first portion.

6 . The turbine airfoil of claim 1 , wherein the first portion meets at an angle between approximately 45° and approximately 90° with the exterior surface of the airfoil wall at the first point, and the second portion meets at an angle between approximately 135° and approximately 175° with the exterior surface of the airfoil wall at the second point.

7 . The turbine airfoil of claim 1 , wherein the cap element includes a thermal barrier coating (TBC), the second portion of each cooling passage extending through the TBC at the second point thereof.

8 . The turbine airfoil of claim 1 , wherein the cap element includes a metal plug in the first portion at or near the first point, and
further comprising a thermal barrier coating (TBC) covering the exterior surface of the airfoil wall, the second portion of each cooling passage extending through the TBC at the second point thereof.

9 . The turbine airfoil of claim 1 , wherein the cap element includes a metal layer across the first portion at the first point, and
further comprising a thermal barrier coating (TBC) covering the exterior surface of the airfoil wall, the second portion of each cooling passage extending through the TBC at the second point thereof.

10 . The turbine airfoil of claim 1 , wherein a portion of the airfoil including the plurality of cooling passages and the cap element includes a coupon coupled to a remaining portion of the body.

11 . The turbine airfoil of claim 1 , wherein a cross-sectional area of the first portion is smaller than a cross-sectional area of the second portion where the second portion intersects the mid-portion of the first portion.

12 . The turbine airfoil of claim 1 , wherein the body includes a base and a tip disposed opposite the base, and a pressure sidewall and a suction sidewall extending between a leading edge and a trailing edge, and wherein the airfoil wall is disposed in the leading edge.

13 . A method of forming a cooling passage in an airfoil wall of an airfoil, the turbine airfoil including a coolant chamber therein, the method comprising:
forming a first portion of the cooling passage, the first portion extending from a first point on an exterior surface of the airfoil wall to the coolant chamber; forming a second portion of the cooling passage, the second portion extending from a second point on the exterior surface of the airfoil wall distal from the first point to intersect a mid-portion of the first portion; and closing the first portion at the first point with a cap element but leaving the second portion open, wherein each cooling passage has a single inlet in fluid communication with the coolant chamber and a single outlet at the second point of the second portion.

14 . The method of claim 13 , wherein each forming includes drilling.

15 . The method of claim 13 , wherein forming the first portion includes drilling from within the coolant chamber outwardly.

16 . The method of claim 13 , wherein forming the second portion includes forming the second point of the second portion to include a diffuser opening in an axially downstream direction from the leading edge.

17 . The method of claim 13 , wherein closing the first portion with the cap element includes forming a thermal barrier coating (TBC) over the exterior surface, the second portion of each cooling passage extending through the TBC at the second point thereof.

18 . The method of claim 13 , wherein closing the first portion with the cap element includes forming a metal plug in the first portion at or near the first point, and
further comprising forming a thermal barrier coating (TBC) over the exterior surface, the second portion of each cooling passage extending through the TBC at the second point thereof.

19 . The method of claim 13 , wherein closing the first portion with the cap element includes joining a metal layer across the first portion at the first point, and
further comprising forming a thermal barrier coating (TBC) over the exterior surface, the second portion of each cooling passage extending through the TBC at the second point thereof.

20 . The method of claim 13 , wherein forming the first portion and the second portion includes forming a cross-sectional area of the first portion smaller than a cross-sectional area of the second portion where the second portion intersects the mid-portion of the first portion.

Assignees

• Gen Electric

Inventors

• Rathay Nicholas William
• Brzek Brian Gene
• Gregg Jason Ray

Classifications

• F01D5/143

  Contour of the outer or inner working fluid flow path wall, i.e. shroud or hub contour · CPC title

• F01D5/18 Primary

  Hollow blades, {i.e. blades with cooling or heating channels or cavities (structure of hollow blades in general F01D5/147)}; Heating, heat-insulating or cooling means on blades · CPC title

• F01D5/186 Primary

  Film cooling (F01D5/187 takes precedence) · CPC title

• F01D5/187

  Convection cooling · CPC title

• F05D2230/10

  by removing material · CPC title