COOLING CHANNEL FOR AIRFOIL WITH TAPERED POCKET
The present invention includes systems and methods for providing cooling channels located within walls of a turbine airfoil. These cooling channels include micro-circuits that taper in various directions along the length and width of the airfoil. In addition, these cooling channels have a variety of shapes and areas to facilitate convective heat transfer between the surrounding air and the airfoil.
1 . An airfoil for a gas turbine having a leading edge and a trailing edge, the airfoil comprising:
an airfoil wall having an inner surface and an outer surface, the airfoil wall forming an airfoil chamber at least partially enclosed by the airfoil wall; and
a plurality of pockets within the airfoil wall, each of the plurality of pockets comprising:
an inner pocket wall and an outer pocket wall;
at least one first opening in the inner surface positioned at a first distance away from the leading edge, the first opening providing fluid communication between the airfoil chamber and the pocket; and
at least one second opening in the outer surface positioned at a second distance away from the leading edge, the second opening providing fluid communication between an outside of the airfoil and the pocket,
wherein a distance between the inner pocket wall and the outer pocket wall is larger proximate the leading edge and smaller proximate the trailing edge.
2 . The airfoil of claim 1 , wherein each of the plurality of pockets further comprises a plurality of pedestals, wherein the plurality of pedestals extend between the inner pocket wall and outer pocket wall of each respective pocket of the plurality of pockets.
3 . The airfoil of claim 2 , wherein each pedestal of the plurality of pedestals of each of the plurality of pockets has a circular, triangular, square, ovular, or rectangular cross-section.
4 . The airfoil of claim 2 , wherein a distance between each of the plurality of pedestals in each of the plurality of pockets is larger proximate the leading edge and smaller proximate the trailing edge.
5 . The airfoil of claim 2 , wherein the plurality of pockets are arrayed in a linear or non-linear pattern within the airfoil wall.
6 . The airfoil of claim 2 , wherein the plurality of pockets within the airfoil wall and the plurality of pedestals are formed using additive manufacturing.
7 . The airfoil of claim 1 , wherein a ratio of cross-sectional area between the inner pocket wall and the outer pocket wall of each of the plurality of pockets is between 1.1:1 and 10:1.
8 . The airfoil of claim 7 , wherein for each of the plurality of pockets, the inner pocket wall and the outer pocket wall are substantially parallel to the inner surface of the airfoil wall.
9 . The airfoil of claim 1 , wherein for each of the plurality of pockets, the second opening is positioned on a pressure side wall or a suction side wall of the airfoil.
10 . The airfoil of claim 1 , wherein a ratio of pocket axial length to airfoil wall width in each of the plurality of pockets is at least 3:1.
11 . The airfoil of claim 1 , wherein the plurality of pockets are arrayed in a radial direction within the airfoil wall, and wherein a ratio of pocket radial height to airfoil wall width in each of the plurality of pockets is at least 3:1.
12 . A gas turbine assembly, the assembly comprising:
an airfoil having a leading edge and a trailing edge, the airfoil comprising an airfoil wall having an inner surface and an outer surface, the airfoil wall forming an airfoil chamber at least partially enclosed by the airfoil wall; and
a plurality of pockets within the airfoil wall, each of the plurality of pockets comprising:
an inner pocket wall and an outer pocket wall;
at least one first opening in the inner surface positioned at a first distance away from the leading edge, the first opening providing fluid communication between the airfoil chamber and the pocket; and
at least one second opening in the outer surface positioned at a second distance away from the leading edge, the second opening providing fluid communication between an outside of the airfoil and the respective pocket,
wherein a distance between the inner pocket wall and the outer pocket wall is larger proximate the leading edge and smaller proximate the trailing edge, and
wherein a ratio of cross-sectional area of the inner pocket wall to the outer pocket wall is between 1.1:1 and 10:1.
13 . The assembly of claim 12 , wherein each of the plurality of pockets further comprises a plurality of pedestals that extend between the inner pocket wall and the outer pocket wall.
14 . The assembly of claim 13 , wherein each pedestal of the plurality of pedestals of each of the plurality of pockets has a circular, triangular, square, ovular, or rectangular cross-section.
15 . The assembly of claim 14 , wherein a distance between each of the plurality of pedestals in each of the plurality of pockets is larger proximate the leading edge and smaller proximate the trailing edge.
16 . The assembly of claim 12 , wherein the plurality of pockets within the airfoil wall are arrayed in a linear or a non-linear pattern.
17 . The assembly of claim 12 , wherein the inner pocket wall and the outer pocket wall of each of the plurality of pockets are substantially parallel to the inner surface of the airfoil wall.
18 . The assembly of claim 12 , wherein the second opening is positioned in a pressure side wall, a suction side wall, or the trailing edge of the airfoil.
19 . The assembly of claim 12 , wherein a ratio of pocket axial length to airfoil wall width in each of the plurality of pockets is at least 3:1.
20 . The assembly of claim 12 , wherein a ratio of pocket radial height to airfoil wall width in each of the plurality of pockets is at least 3:1.
21 . A method of manufacturing airfoils, the method comprising:
providing an airfoil having a leading edge and a trailing edge, the airfoil having an airfoil wall having an inner surface and an outer surface, the airfoil wall forming an airfoil chamber at least partially enclosed by the airfoil wall; and
forming a plurality of pockets within the airfoil wall, each of the plurality of pockets comprising:
an inner pocket wall and an outer pocket wall;
a first opening in the inner surface positioned at a first distance away from the leading edge, the first opening providing fluid communication between the airfoil chamber and the pocket; and
a second opening in the outer surface positioned at a second distance away from the leading edge, the second opening providing fluid communication between an outside of the airfoil and the pocket,
wherein a distance between the inner pocket wall and the outer pocket wall is larger proximate a leading edge of the airfoil and smaller proximate a trailing edge of the airfoil.
22 . The method of claim 21 , wherein the pocket is formed using additive manufacturing.
23 . The method of claim 21 , wherein a ratio of pocket axial length to airfoil wall width for each of the plurality of pockets is at least 3:1.
24 . The method of claim 21 , wherein a ratio of pocket radial height to airfoil wall width for each of the plurality of pockets is at least 3:1.
25 . The method of claim 21 , wherein each of the plurality of pockets further comprises a plurality of pedestals, wherein the plurality of pedestals extend between the inner pocket wall and outer pocket wall of each respective pocket of the plurality of pockets.