Combustor Assembly Thermal Expansion Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engines face challenges in attaching ceramic matrix composite (CMC) liners to metallic dome structures due to differing coefficients of thermal expansion, which complicates airflow control and mechanical coupling.
Innovation Solution
A combustor assembly design featuring a cap assembly with resilient members to form a seal and accommodate thermal expansion, allowing for secure attachment of CMC liners to metallic domes while controlling airflow through specialized mounting assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If CMC materials are used for liners to withstand extreme temperatures, then temperature resistance is improved, but thermal expansion compatibility with metal dome structures deteriorates
Solution Approach 1:
A mounting assembly acts as an intermediary component between the CMC liner and metal dome structure. This mounting assembly includes a first portion attached to the dome and a second portion attached to the liner, with a resilient member that accommodates differential thermal expansion between the two materials, enabling reliable attachment despite incompatible thermal properties
Solution Approach 2:
The resilient member changes its physical parameters (elastic deformation) in response to thermal expansion differences. As temperature varies, the resilient member elastically deforms to accommodate the differential expansion between CMC and metal, maintaining attachment reliability across temperature ranges
2Strength
If CMC liners are attached to metal dome structures, then structural integrity is improved, but control of high-pressure airflow through connection points deteriorates
Solution Approach 1:
The mounting assembly serves as a mediator that simultaneously provides structural attachment and airflow control. The resilient member seals the connection between the liner and dome while accommodating thermal expansion, and the structure includes features to control high-pressure airflow through the connection point
Solution Approach 2:
The mounting assembly performs multiple functions: it provides structural attachment between dissimilar materials, accommodates thermal expansion, seals the connection to control airflow, and manages high-pressure gas flow. This multi-functional design integrates attachment and airflow control into a single component system
3Reliability
If resilient members are used to accommodate thermal expansion, then thermal expansion compatibility is improved, but device complexity increases
Solution Approach 1:
The resilient member functions as a flexible element within the mounting assembly that accommodates thermal expansion through elastic deformation. This flexible component allows the rigid mounting structure to adapt to thermal changes without requiring complex adjustment mechanisms
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 design effectively manages relative thermal expansion between CMC liners and metal domes, ensuring a controlled airflow and secure attachment, enhancing the operational efficiency and reliability of gas turbine engines.
Implementation Method 1
a resilient member configured to form a seal between the metal dome and the CMC liner when the mounting assembly is positioned over the forward end of the CMC liner
Implementation Method 2
a resilient member configured to form a seal between the metal dome and the CMC liner when the mounting assembly is positioned over the forward end of the CMC liner
Data Source
AI summary
A combustor assembly for a gas turbine engine is provided. The combustor assembly includes a liner at least partially defining a combustion chamber and extending between an aft end a forward end generally along an axial direction. The combustor assembly also includes an annular dome including an enclosed surface defining a slot for receipt of the forward end of the liner. A cap is positioned at the forward end of the liner and at least partially positioned within the slot defined by the enclosed surface of the annular dome. The cap includes a surface configured to contact at least one of the enclosed surface of the annular dome and the forward end of the liner. Such a configuration may form a substantially airtight seal between the forward end of the liner and the annular dome despite a relative thermal expansion between the components.