Jet Engine Mid-Turbine Frame Seal Design
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Solution Overview
Problem
Conventional mid-turbine frames in jet engines face inefficiencies due to hot gases impairing high-temperature intolerant components, and existing seals fail to effectively modulate cooling air flow while maintaining thermal protection across varying temperatures.
Innovation Solution
A seal configuration that joins and thermally protects structures, while defining a controlled path for cooling air to flow, using a combination of T-shaped elements and a perforated structure with tortuous gutters to channel cooling air through the hot gas flow path, allowing for expansion and contraction with temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional seals are used in mid-turbine frames, then structural simplicity is maintained, but thermal protection effectiveness deteriorates due to inability to modulate cooling air flow
Solution Approach 1:
The seal is divided into multiple functional segments including T-shaped elements, perforated structures, and tortuous gutters. Each segment performs a specific function: T-shaped elements provide structural support and sealing, perforated structures modulate cooling air flow, and tortuous gutters channel and direct the cooling air. This segmentation allows the seal to achieve effective thermal protection through coordinated action of specialized components.
Solution Approach 2:
The seal incorporates dynamic flow modulation capabilities through its perforated structure and tortuous gutters. The cooling air flow is dynamically controlled as it passes through the perforations and follows the tortuous path, allowing the seal to adaptively modulate cooling effectiveness based on thermal conditions while maintaining structural integrity.
2Ease of manufacture
If existing seals are used, then manufacturing simplicity is maintained, but cooling air flow modulation capability deteriorates
Solution Approach 1:
The seal incorporates a perforated structure that functions as a porous element for flow modulation. The perforations are strategically positioned and sized to control cooling air flow rates and distribution. This porous approach enables effective cooling air modulation while maintaining manufacturing feasibility through standardized perforated component fabrication.
Solution Approach 2:
The tortuous gutters act as intermediary channels that mediate between the cooling air source and the components requiring thermal protection. These gutters guide and condition the cooling air flow, distributing it effectively to cool high-temperature intolerant components while integrating with the overall seal structure.
3Device complexity
If simple seal structures are used, then device complexity is reduced, but thermal protection across varying temperatures deteriorates
Solution Approach 1:
The seal applies local quality by providing different structural and functional characteristics at different locations. The T-shaped elements provide localized structural support and sealing at joint areas, while perforated structures are positioned where cooling air modulation is most needed, and tortuous gutters are routed to specifically protect heat-sensitive components. This localized optimization enables effective thermal protection across varying temperature zones.
Solution Approach 2:
The seal structure employs nesting by integrating multiple functional elements within a compact configuration. The tortuous gutters are nested within the seal body, the perforated structures are embedded in the seal components, and the T-shaped elements are integrated into the joint assemblies. This nested arrangement achieves comprehensive thermal protection functionality within a space-efficient 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 seal effectively cools high-temperature intolerant components by modulating cooling air flow, maintaining thermal protection and aerodynamic efficiency across temperature variations, enhancing the performance of mid-turbine frames in jet engines.
Implementation Method 1
defining a controlled path for cooling air to flow, using a combination of T-shaped elements and a perforated structure with tortuous gutters to channel cooling air through the hot gas flow path
Implementation Method 2
allowing for expansion and contraction with temperature changes
Data Source
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AI summary
A mid-turbine frame (MTF") for a jet engine is disclosed and comprises a duct that extends between a high pressure turbine ("HPT") and a low pressure turbine ("LPT"), the duct comprising a plurality of segments that together form an outer annular structure and an inner annular structure, the inner annular structure situated radially inward of the outer annular structure, and/or a plurality of vanes that extend radially outward from the inner annular structure toward the outer annular structure, each vane comprising a channel. Each segment may be coupled to an adjacent segment by a seal.