Trimmable Angel Wing Seal for Multi-Frame Turbomachine Buckets
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Solution Overview
Problem
Conventional turbomachine buckets are not interchangeable across different sized turbomachine frames due to varying geometries, leading to inefficiencies and the need for new castings, as the angel wing and discourager sizes must match precisely to prevent gas leakage and maintain performance.
Innovation Solution
A turbomachine bucket design with an axially extending tip that can be modified by adding or removing material to accommodate different sized discouragers, allowing for sealing with variously sized discouragers, thereby enabling compatibility with multiple turbomachine frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional buckets with fixed angel wings are used, then sealing performance with matching discouragers is improved, but interchangeability between different sized frames deteriorates
Solution Approach 1:
The angel wing is designed with a trimable tip that can be adjusted to different lengths, transforming a static component into a dynamic one. This allows the same bucket to adapt to different discourager sizes by modifying the angel wing length, thereby achieving interchangeability across different frame sizes while maintaining proper sealing clearance.
Solution Approach 2:
The invention changes the physical parameter of the angel wing length through material removal or addition at the tip. By adjusting this dimension parameter, the bucket can accommodate various discourager sizes while maintaining the optimal clearance for sealing performance, resolving the contradiction between fixed geometry and adaptability.
2Manufacturing precision
If new castings are manufactured for each frame size, then precise sealing clearance is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The invention separates the angel wing into a main body (cast with the bucket) and a trimable tip portion. This segmentation allows the majority of the component to be manufactured once with high precision, while only the tip requires adjustment, reducing overall manufacturing complexity compared to creating entirely new castings for each size.
Solution Approach 2:
The angel wing is initially manufactured with a preliminary oversized tip that can subsequently be trimmed to the required length. This preliminary action of casting with extra material allows for precise final dimensions to be achieved through simple material removal, rather than requiring multiple precise castings for different sizes.
3Area of stationary object
If angel wings are made larger to fit smaller discouragers, then coverage is improved, but overlap and cooling performance deteriorate
Solution Approach 1:
Instead of using a universally large angel wing that would overlap excessively with smaller discouragers, the invention allows dynamic adjustment of the angel wing length. This ensures each angel wing has the precise coverage area needed for its specific discourager size, preventing excessive overlap that would disrupt cooling flows and cause energy loss.
Data Source
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AI summary
A turbomachine bucket (120) includes an airfoil (124), a shank (126) coupled to the airfoil, and an angel wing seal (122) coupled to the shank, the angel wing seal having an axially extending tip (128) sized to seal with a plurality of discouragers (130) used in different turbomachines, each discourager having a different axial extent. Various methods for modifying the angel wing seal to accommodate different sized discouragers, either by means of attaching a material section to the axially extending tip or removing a portion of the axially extending tip, are also disclosed.