Turbine Blade Squealer Tip Rails With Embedded Cooling Channels
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Solution Overview
Problem
Turbine blade tips face challenges in cooling due to their location away from internal cooling passages, leading to reduced efficiency and potential oxidation, which increases tip clearance and reduces turbine performance.
Innovation Solution
The implementation of additively manufactured squealer tip rails with embedded cooling channels, connected to cooling holes in the tip floor, providing enhanced cooling and reducing coolant consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If squealer tip rails are located at a distance from internal cooling passages, then the tip structure can be simplified, but the cooling effectiveness deteriorates
Solution Approach 1:
The patent merges the squealer tip rail structure with the cooling system by integrating embedded cooling channels directly into the tip rails. This combination allows the tip rails to serve dual functions: maintaining tip clearance and providing effective cooling, thereby resolving the contradiction between structural simplicity and cooling effectiveness.
Solution Approach 2:
The patent transitions from traditional through-cooling holes to three-dimensional embedded cooling channels within the tip rails. This dimensional change enables cooling pathways that follow the contours of the tip rails, significantly improving cooling effectiveness while maintaining structural integrity and simplicity.
2Temperature
If cooling holes are drilled on pressure side surface and tip cap, then cooling can be provided, but coolant consumption increases
Solution Approach 1:
The patent applies local quality by concentrating cooling channels specifically within the tip rails where heat transfer is most critical. This localized cooling approach provides effective temperature control at the tip while reducing overall coolant consumption compared to traditional distributed cooling hole patterns.
Solution Approach 2:
By transitioning from two-dimensional cooling hole patterns on surfaces to three-dimensional embedded channels within the tip rails, the patent achieves more efficient heat removal. The embedded channels are positioned optimally within the thermal gradient, improving cooling effectiveness and reducing the quantity of coolant needed.
3Temperature
If embedded cooling channels are added to tip rails, then cooling effectiveness improves, but manufacturing complexity increases
Solution Approach 1:
The patent utilizes additive manufacturing technology, which fundamentally changes the manufacturing parameters and capabilities. This manufacturing approach enables the creation of complex embedded cooling channel geometries that would be impossible or extremely difficult to achieve with traditional manufacturing methods, thereby resolving the contradiction between cooling effectiveness and manufacturing complexity.
Solution Approach 2:
The patent replaces traditional mechanical manufacturing processes (drilling, machining) with additive manufacturing. This substitution enables the direct formation of embedded cooling channels within the tip rails during the manufacturing process itself, eliminating the need for complex post-processing operations and reducing overall manufacturing complexity despite the intricate channel geometries.
4Length of moving object
If tip rails are extended radially outward, then tip clearance is reduced, but heat transfer area increases leading to higher thermal stress
Solution Approach 1:
The patent introduces embedded cooling channels as an intermediary thermal management system within the tip rails. These channels act as a mediator that actively removes heat from the extended tip rails, preventing excessive thermal stress accumulation. The cooling channels enable the tip rails to extend further radially while maintaining thermal integrity and stress levels within acceptable limits.
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 design improves thermal performance by placing cooling channels closer to the area of highest heat transfer, reduces tip leakage flow, and extends blade life by controlled film coverage and segregated cooling circuits.
Implementation Method 1
The at least one squealer tip rail comprises an embedded cooling channel formed therein. The embedded cooling channel is aligned with and fluidically connected to the at least one cooling hole formed through the tip floor of the airfoil section.
Implementation Method 2
The tip cap comprises at least one squealer tip rail extending outward from the tip floor. The tip cap is formed via layer-by-layer deposition of material directly over the tip floor of the airfoil section.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A turbine blade (1) includes an airfoil section (10), wherein at least one cooling hole (32) is formed a tip floor (30) of the airfoil section (10), which is fluidically connected to an internal coolant cavity (28) of the airfoil section (10). The turbine blade (1) further includes an additively manufactured tip cap (40) formed via layer-by-layer deposition of material directly over the tip floor (30) of the airfoil section (10). The tip cap (40) includes at least one squealer tip rail (42, 44) extending outward from the tip floor (30). The at least one squealer tip rail (42, 44) comprises an embedded cooling channel (50) formed therein. The embedded cooling channel (50) is aligned with and fluidically connected to the at least one cooling hole (32) formed through the tip floor (30) of the airfoil section (10). The embedded cooling channel (50) comprises one or more outlets (54, 56) located on at least one of a side face (42a, 44b) and a top face (42c, 44c) of the at least one squealer tip rail (42, 44).