Turbine airfoil with internal cooling channels

Abstract

A turbine airfoil (10) with an internal cooling system (12) having one or more bladders (14) forming near-wall cooling channels (16) is disclosed. The bladder (14) may be conformed to a shape of an inner surface (44) forming a cavity (18) within the internal cooling system (12). One or more standoff ribs (56) may extend radially inward from the inner surface (44) forming the cavity (18) to maintain the bladder (14) in position off of the inner surface (44) so that the near-wall cooling channel (16) is formed between the bladder (14) and the inner surface (44). The near-wall cooling channel (16) may be formed by inserting a bladder (14) into the cavity (18) in a first insertable position (22) and expanding the bladder (14) into a second expanded position (24). In at least one embodiment, the chamber (26) formed by the bladder (14) may be dead space that does not contain cooling fluids as a part of the cooling system (12).

Description

FIELD OF THE INVENTION[0001]This invention is directed generally to gas turbine engines, and more particularly to internal cooling systems for airfoils in gas turbine engines.BACKGROUND[0002]Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. Typical turbine combustor configurations expose turbine vane and blade assemblies to high temperatures. As a result, turbine vanes and blades must be made of materials capable of withstanding such high temperatures, or must include cooling features to enable the component to survive in an environment which exceeds the capability of the material. Turbine engines typically include a plurality of rows of stationary turbine vanes extending radially inward from a shell and include a plurality of rows of rotatable turbine blades attached to a rotor assembly for turning the rotor.[0003]Typically, the turb...

AI Technical Summary

Benefits of technology

The patent text is about an internal cooling system for making metal parts. The system has several advantages compared to traditional methods. Firstly, it can be created in a simple way and is better for complex cooling configurations. Secondly, it allows for greater precision and control over the cooling process. These technical effects can improve the quality and efficiency of metal part production.

Problems solved by technology

However, the four wall design has an inherent structural problem due to the significant differences in operating temperatures between the outer and inner walls.

This difference in operating temperature between the inner and outer walls creates high thermally induced stress in the walls and can greatly limit the life of the airfoils.

In addition, forming complex cores required for multiwall definition in turbine airfoils formed by investment casting is challenging.

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