CMC Combustor Deflector Retention for High-Temperature Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metal combustor deflectors in gas turbine engines are prone to damage from high temperatures, leading to unscheduled maintenance and component failure, while traditional materials limit engine performance and durability.
Innovation Solution
Employing ceramic matrix composite (CMC) deflectors with bayonet and tongue-and-groove joints, along with spring retention, to securely attach the deflector to the combustor dome, allowing for higher temperature resistance and reduced cooling needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal combustor deflectors are used, then the deflectors can be manufactured with traditional materials and processes, but the deflectors are prone to damage from high temperatures, metal oxidation, and thermal barrier coating chipping, leading to unscheduled maintenance
Solution Approach 1:
The patent applies composite materials by combining a metallic substrate with a ceramic thermal barrier coating layer. This composite structure allows the metal substrate to provide structural strength while the ceramic coating protects against high temperature damage and oxidation, thereby improving deflector durability without sacrificing mechanical properties
Solution Approach 2:
The patent changes the material parameters by transitioning from uncoated metal to metal with thermal barrier coating, and further to CMC materials. This parameter change enables the deflector to withstand higher temperatures and resist oxidation, directly addressing the temperature damage issue while maintaining structural integrity
2Temperature
If traditional metal deflectors are used, then manufacturing is simpler, but engine operating temperatures are limited and cooling requirements increase
Solution Approach 1:
The thermal barrier coating and CMC materials enable higher engine operating temperatures by providing thermal insulation. This allows the engine to operate at elevated temperatures without excessive heat transfer to the metal substrate, reducing cooling requirements and improving thermal efficiency
Solution Approach 2:
By changing the material composition to include ceramic coatings and CMC materials, the patent enables the deflector to withstand higher temperatures. This parameter change directly increases the maximum engine operating temperature while reducing the energy required for cooling
3Reliability
If CMC deflectors are used, then temperature resistance and durability are improved, but the assembly mechanism becomes more complex with bayonet and tongue-and-groove joints
Solution Approach 1:
The patent applies segmentation by dividing the deflector into modular components with standardized bayonet and tongue-and-groove joints. This allows the complex CMC deflector to be assembled from discrete segments, facilitating installation and replacement while maintaining the durability benefits of CMC materials
Solution Approach 2:
The bayonet and tongue-and-groove joint mechanisms serve multiple functions: they provide mechanical connection, alignment, and retention for the CMC deflector segments. This universal joint design simplifies the overall assembly process despite the complexity of the CMC material itself
Data Source
AI summary
Combustor dome assemblies having combustor deflectors are provided. For example, a combustor dome assembly comprises a combustor dome defining an opening; a ceramic matrix composite (CMC) deflector positioned adjacent the combustor dome on an aft side of the assembly; a fuel-air mixer defining a groove about an outer perimeter thereof; and a seal plate including a key. The CMC deflector includes a cup extending forward through the opening in the combustor dome that defines one or more bayonets and a slot. The bayonets are received in the fuel-air mixer groove, and the seal plate key is received in the CMC deflector slot. In another embodiment, where the seal plate may be omitted, a spring is positioned between the fuel-air mixer and the CMC deflector to hold the CMC deflector in place with respect to the combustor dome. Methods of assembling combustor dome assemblies having CMC deflectors also are provided.