Labyrinth Seal Bypass Passage for Air Flow Regulation
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Solution Overview
Problem
Labyrinth seals in gas turbine engines face challenges in regulating air flow due to thermal and mechanical movements, leading to restricted air flow and potential hot gas ingestion, which can cause damage or failure of engine components.
Innovation Solution
A labyrinth seal design featuring an abradable lining and fins with a bypass passage that allows a metered air flow independent of the relative positions of the components, ensuring consistent air flow and reducing the criticality of air flow regulation through the labyrinthal path, thereby allowing the fins and abradable material to operate in close contact for improved engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the distance between the abradable lining and fins is reduced to allow sufficient air flow through the seal, then air flow restriction is prevented, but air leakage increases and performance efficiency decreases
Solution Approach 1:
The seal air flow is segmented into two independent paths: the labyrinthal path through the fins and abradable lining, and the bypass passage through the abradable lining. This segmentation allows each path to serve a specific function - the labyrinthal path provides resistance to minimize air leakage, while the bypass passage ensures sufficient air flow independent of relative component positions
Solution Approach 2:
The bypass passage acts as an intermediary flow path that mediates between the conflicting requirements of air flow sufficiency and air leakage minimization. By providing an alternative route through the abradable lining, it ensures adequate air flow without requiring the fins and lining to be positioned far apart, thus maintaining the effectiveness of the labyrinthal path in restricting air leakage
2Object-affected harmful factors
If the distance between the abradable lining and fins is increased to prevent hot gas ingestion, then component protection is improved, but air flow restriction increases and performance efficiency decreases
Solution Approach 1:
The air flow path is segmented into the labyrinthal path for minimizing air leakage and the bypass passage for ensuring sufficient air flow and cooling. This allows the fins and abradable lining to be positioned in close contact for high engine performance while the bypass passage independently ensures adequate cooling air flow to prevent hot gas ingestion
Solution Approach 2:
Different regions of the seal serve different functions: the labyrinthal path region provides resistance to air leakage, while the bypass passage region provides a dedicated cooling air flow path. This local differentiation allows the seal to simultaneously achieve both air leakage minimization and sufficient cooling air flow
3Loss of energy
If the fins and abradable lining are positioned in close contact for high engine performance, then air leakage is minimized, but air flow restriction increases during thermal and mechanical movements
Solution Approach 1:
The air flow is segmented into two independent paths: the labyrinthal path through the fins and abradable lining for minimizing air leakage, and the bypass passage through the abradable lining for ensuring sufficient air flow. This segmentation allows the fins and lining to be positioned in close contact for high engine performance while the bypass passage independently ensures adequate air flow during thermal and mechanical movements
Solution Approach 2:
The bypass passage is designed to accommodate thermal and mechanical movements of the engine components. As the relative positions of the fins and abradable lining change during operation, the bypass passage maintains its functionality in providing sufficient air flow, making the overall seal design dynamic and adaptable to operating conditions
Data Source
AI summary
A labyrinth seal is provided for forming a seal between a first and a second component which rotate relative to each other. The seal has an abradable lining mounted to the first component, and a plurality of fins projecting from the second component. The fins are arranged in abutment with the abradable lining to form a labyrinthal path for a flow of air through the seal. The seal further has a bypass passage which extends through the abradable lining. The bypass passage allows air to flow through the seal and bypass the labyrinthal path.