Braze-Modified Turbine Blade Passages for Tip Shroud Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Turbine blades in gas turbine engines face challenges in efficiently managing heat transfer along their radial length due to constant diameter cooling passages, leading to inadequate cooling in tip shroud regions and potential sealing issues with thin wall thicknesses, which can compromise their ability to withstand high temperatures.
Innovation Solution
A process involving the insertion of a braze material into cooling passages, blocking ends, heat treating with an elongated member to form a solid interior, and machining to create modified passages with varying diameters, enhancing cooling efficiency and sealing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If constant diameter cooling passages are used in turbine blades, then the manufacturing process is simplified, but cooling efficiency in tip shroud regions deteriorates due to excessive heat transfer before cooling fluid reaches the region
Solution Approach 1:
The cooling passage diameter is varied along its length to match local cooling requirements. The passage has a larger diameter in regions requiring more cooling (such as near the tip shroud) and a smaller diameter in regions where less cooling is needed, optimizing heat transfer efficiency throughout the blade structure.
Solution Approach 2:
The diameter parameter of the cooling passage is changed along its length rather than maintaining a constant value. This parameter variation allows the cooling system to adapt to different thermal loads at different locations within the turbine blade, improving overall cooling performance.
2Temperature
If multiple cooling passages are provided in blade tip shroud, then cooling coverage is improved, but wall thickness becomes too thin requiring sealing processes
Solution Approach 1:
An elongated member is inserted into the cooling passage and surrounded by braze material, creating a nested structure. This allows the passage walls to be thin for cooling efficiency while the braze material provides the necessary structural strength and sealing capability.
Solution Approach 2:
The cooling passage structure combines the base blade material with braze material to create a composite structure. The braze material reinforces thin-walled passages, providing both structural integrity and sealing functionality while maintaining the thin wall design for effective cooling.
3Temperature
If wall thickness is reduced to accommodate multiple cooling passages, then cooling efficiency improves, but sealing capability deteriorates
Solution Approach 1:
The braze material acts as an intermediary substance that fills the cooling passage and bonds to the passage walls. This intermediary layer provides sealing capability while allowing the passage walls themselves to remain thin for cooling efficiency, transferring both thermal and mechanical properties between the cooling fluid and the blade structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This process allows for the formation of passages with desired thickness and geometry, improving heat management and sealing, thereby enhancing the turbine blade's ability to withstand high temperatures and maintain efficiency.
Implementation Method 1
heat treating the passage, the first material, and the elongated member to form a solid interior in the component
Implementation Method 2
inserting the braze material into the passage by applying negative pressure to the passage to pull braze material into the passage
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A process of modifying a passage (88, 310) in a component (300) is provided. The process includes inserting a first material into the passage (88, 310); blocking at least one end (311, 311a, 311b) of the passage (88, 310); inserting an elongated member (316) into the passage (88, 310) through the first material; heat treating the passage (88, 310), the first material, and the elongated member (316) to form a solid interior (317) in component (300); and machining through the solid interior (317) to form a modified passage (88, 310) in the component (300).