Curved Divoted Baffle Insert for Airfoil Cooling
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Solution Overview
Problem
Existing baffle designs for impingement cooling of airfoil vanes in gas turbine engines are complex and costly to manufacture, making it difficult to control the distribution of cooling air effectively, especially in thin-walled structures where altering the trajectory of cooling air is challenging.
Innovation Solution
A baffle insert with a liner forming a hollow body featuring divoted segments and multiple columns of cooling holes, where the divots are elongate and curved to direct cooling air at specific angles, focusing the air at common locations to enhance cooling efficiency, particularly at hotspots on the airfoil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If a thin-walled baffle structure is used to maintain lightweight design, then weight is reduced, but the ability to control and direct cooling air trajectory is compromised
Solution Approach 1:
The patent employs curved divots with specific radii of curvature to redirect cooling air jets. The divots are formed with precise curvature profiles that refract the cooling air flow at predetermined angles, enabling effective trajectory control without requiring thick baffle walls. The curved geometry allows thin-walled baffles to successfully direct cooling air to target hotspots on the airfoil surface.
2Manufacturing precision
If complex baffle designs with multiple shaping and assembly steps are implemented to improve cooling air distribution, then cooling air control is enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The baffle design incorporates segmented divots that can be formed as integral features of the baffle structure or as separate inserts. These divot segments are positioned at specific locations to target different hotspot regions. The segmentation allows for simplified manufacturing of individual components that can be assembled into the complete cooling system, reducing overall manufacturing complexity while maintaining precise cooling air distribution control.
Solution Approach 2:
The patent utilizes controlled changes in divot geometric parameters, including depth, width, and curvature radius, to optimize cooling air refraction. By carefully selecting these parameters, the design achieves effective cooling air direction with simpler manufacturing processes. The parameter optimization allows standard fabrication methods to produce the required precision without extensive shaping and assembly steps.
3Area of stationary object
If cooling air is directed at angles oblique to the airfoil surface, then cooling coverage area is increased, but cooling air focus at specific hotspot locations is reduced
Solution Approach 1:
The curved divot profiles are specifically designed to refract cooling air jets at controlled angles while maintaining focus at target hotspot locations. The curvature geometry creates a refraction effect that spreads cooling air coverage across the airfoil surface while simultaneously concentrating the cooling effect at predetermined focal points. This dual functionality resolves the contradiction between wide coverage and precise focus.
Solution Approach 2:
The divot structure acts as a nested flow control element within the baffle, creating a focused cooling jet that emerges from the divot and impinges on the airfoil surface. The nested geometry of the divot channels and focuses the cooling air, allowing oblique angle coverage while maintaining precision at the impingement point through the nested flow path design.
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
The solution allows for a simpler, cost-effective baffle design that effectively directs cooling air to hotspots on the airfoil, improving cooling efficiency and reducing manufacturing complexity while maintaining the thin-walled, lightweight structure of the baffle.
Implementation Method 1
the first and second curved segments are curved to direct air through the first and second columns of cooling holes at angles oblique to an interior surface of the airfoil, and the elbow segment is curved to direct air through the third column of cooling holes at an angle normal to the profile of the baffle and the interior surface of the airfoil
Implementation Method 2
the cooling air is passed into an interior of the airfoil to remove heat from the alloy. The cooling air is subsequently discharged through cooling holes in the airfoil to pass over the outer surface of the airfoil
Data Source
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AI summary
A baffle insert (18) for an internally cooled airfoil (12) comprises a liner, a divoted segment (28,30) and a plurality of cooling holes (32,34). The liner has a continuous perimeter formed to shape a hollow body having a first end and a second end. The divoted segment of the hollow body is positioned between the first end and the second end. The plurality of cooling holes is positioned on the divoted segment to aim cooling air exiting the baffle insert at a common location.