Compliant Seal Fitting for Ceramic Probe Positioning in Gas Turbine Hot Gas Paths
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Solution Overview
Problem
Ceramic probes are difficult to hold and seal in hot, high-flow gas paths of gas turbine engines, as existing sealing techniques are prone to leaks and can damage the ceramic probes, especially when transitioning from ceramic to metal components.
Innovation Solution
A fitting with a main body attachable to the casing, featuring an internal bore with cooling holes and a compliant seal, along with a follower and fastener that deforms the seal to secure and seal the probe, minimizing heat transfer and preventing damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional sealing techniques are used to seal the ceramic probe, then the sealing structure is simple, but the sealing effectiveness is poor and leaks occur
Solution Approach 1:
The patent employs a flexible bellows-like seal structure that can deform to conform to the ceramic probe surface, creating an effective seal. The flexible membrane or bellows structure adapts to the probe geometry while maintaining sealing pressure, solving the leak problem without requiring complex rigid sealing mechanisms.
Solution Approach 2:
The sealing structure utilizes changes in physical parameters such as pressure and deformation to achieve sealing. The bellows structure can expand or contract to maintain contact with the probe surface under varying thermal and pressure conditions, ensuring reliable sealing in the hot gas path environment.
2Reliability
If rigid sealing methods are used to secure the ceramic probe, then the probe is firmly held, but the ceramic probe is prone to damage
Solution Approach 1:
The flexible seal structure provides gentle, conforming contact with the ceramic probe rather than rigid clamping. This flexible enclosure secures the probe through distributed pressure and geometric constraint while avoiding localized stress concentrations that could cause ceramic fracture.
Solution Approach 2:
The bellows-like flexible structure acts as a cushioning element between the rigid fitting body and the fragile ceramic probe. It absorbs and distributes mechanical stresses, preventing direct transmission of rigid forces to the ceramic probe that could cause damage during installation or operation.
3Object-affected harmful factors
If the seal is made more compliant to protect the ceramic probe, then probe damage is reduced, but sealing reliability decreases
Solution Approach 1:
The flexible bellows structure inherently combines compliance with sealing effectiveness. The flexible material deforms to match the probe surface geometry, ensuring continuous contact and sealing, while its elasticity allows it to accommodate probe dimensions without rigid forcing, thus protecting the ceramic.
Solution Approach 2:
The seal structure is designed to be dynamically adaptable rather than statically fixed. It can deform and adjust its shape in response to thermal expansion, pressure changes, and probe positioning variations, maintaining both sealing integrity and probe protection under varying operating conditions.
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 fitting effectively secures and seals ceramic probes in hot gas paths, preventing leaks and damage while maintaining efficiency and reliability, and allows for cooling to prevent overheating.
Implementation Method 1
one or more cooling holes in communication with the internal bore
Implementation Method 2
the follower may deform the compliant seal about the probe within the main body to secure and seal the probe within the main body
Data Source
AI summary
A fitting for positioning a probe in a hot gas path within a casing of a gas turbine engine is disclosed herein. The fitting includes a main body attachable to the casing opposite the hot gas path. The main body includes an internal bore and one or more cooling holes in communication with the internal bore. A compliant seal is positionable within the internal bore. In addition, a follower is positionable within the internal bore adjacent to the compliant seal. Moreover, the fitting includes a fastener configured to mate with the main body. In this manner, the follower deforms the compliant seal about the probe within the main body to secure and seal the probe within the main body.