Cross Key Connectors for CMC Combustor Liners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metal fasteners used to secure ceramic matrix composite (CMC) liners in gas turbine combustors lose strength and may melt at high operating temperatures, undermining the desired high-temperature capability of CMCs.
Innovation Solution
A combustor assembly featuring a metallic case with cross key connectors that use pins with threaded heads to establish secure connections with ceramic matrix composite liners, eliminating the need for fasteners that extend through the liner's internal cavity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metal fasteners are used to secure CMC liners, then the liner can be attached to the case, but the fasteners lose strength and may melt at high operating temperatures
Solution Approach 1:
The patent extracts the fastener from the high-temperature zone by using blind holes that do not penetrate through the liner, isolating the fastener in a cooler region while still achieving secure attachment of the CMC liner to the case
Solution Approach 2:
The blind hole structure acts as an intermediary mechanism that transfers the securing function away from temperature-sensitive metal fasteners, allowing the fastener to operate in a cooler environment while still providing the necessary mechanical connection
2Strength
If fasteners are cooled to maintain strength, then the fastener can withstand high temperatures, but the desired high temperature capability of CMC is undermined
Solution Approach 1:
The patent segments the thermal environment by creating a thermal boundary at the blind hole interface, allowing the fastener to exist in a cooler segment while the CMC liner operates in the high-temperature segment, thus preserving the high temperature capability of the CMC system
Solution Approach 2:
The blind hole configuration creates localized thermal management where only the fastener region experiences cooling, while the rest of the CMC liner maintains its high temperature operation, preserving the overall high temperature capability of the system
3Ease of manufacture
If metal alloy combustor liners are used, then they can be manufactured with existing technology, but significant cooling is required to maintain operating temperatures
Solution Approach 1:
The patent employs CMC (ceramic matrix composite) materials for the liner, which combine the benefits of high-temperature resistance with manufacturability, eliminating the need for significant cooling systems required by metal alloys while maintaining ease of manufacture through established ceramic forming processes
Data Source
AI summary
A combustor adapted for use in a gas turbine engine is disclosed. The combustor includes a metallic case forming a cavity and a ceramic liner arranged in the cavity of the metallic case. The ceramic liner defines a combustion chamber in which fuel is burned during operation of a gas turbine engine. The ceramic liner is located in the metallic case using a plurality of cross key connectors.