Combustor Shell Spacer Mounting for Thermal Expansion Stability
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Solution Overview
Problem
Combustor panels in gas turbine engines often buckle and crack due to thermal expansion issues, as they are not designed to accommodate increased temperatures effectively during operation.
Innovation Solution
A combustor shell with an oblong aperture and a spacer system that includes flanges and threads, allowing for a press-fit attachment of combustor panels, which provides a secure and thermally stable mounting mechanism by maintaining constant friction force during temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If combustor panels are attached directly to the combustor shell through oblong holes, then the structure is simple and easy to manufacture, but the panels buckle and crack due to thermal expansion at increased temperatures
Solution Approach 1:
A spacer is introduced as an intermediary component between the combustor panel and the combustor shell. The spacer extends through the oblong hole in the combustor shell and provides a mounting surface for the panel, allowing thermal expansion while maintaining secure attachment. This mediator resolves the contradiction by adding a component that enables both reliability under thermal stress and manageable structural complexity.
Solution Approach 2:
The attachment system is segmented into distinct functional components: the oblong hole in the combustor shell, the spacer that fits through the hole, and the mounting feature on the panel. This segmentation allows each component to perform its specific function - the oblong hole provides clearance, the spacer provides expansion accommodation, and the mounting feature provides secure attachment - thereby achieving reliable attachment without excessive overall complexity.
2Stability of the object's composition
If combustor panels are allowed to thermally expand freely, then thermal stress is reduced, but the panels become loose and detach from the combustor shell
Solution Approach 1:
The spacer is designed with specific dimensional parameters that change in response to thermal conditions. The oblong shape of the hole and the corresponding spacer geometry allow for controlled dimensional changes during thermal expansion while maintaining attachment strength. The parameters of the spacer (length, width, fit tolerance) are optimized to accommodate expansion while preventing detachment.
Solution Approach 2:
The attachment system is designed to be dynamic rather than rigid. The oblong hole and spacer configuration allows the panel to move dynamically with thermal expansion while remaining attached. The system adapts to changing thermal conditions during operation, maintaining both stability and attachment strength through controlled movement within the oblong aperture.
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 solution ensures that combustor panels remain securely attached and resistant to thermal mechanical fatigue, preventing buckling and cracking, thereby enhancing the durability and reliability of gas turbine engines.
Implementation Method 1
maintaining constant friction force during temperature changes
Implementation Method 2
the spacer may be press fit into the combustor shell
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
A combustor shell (104, 184) is provided. The combustor shell (104, 184) may include a first aperture (111) at least partially defined by an inner wall (149) of the combustor shell (104, 184) and passing from a diffuser-facing side (141) of the combustor shell (104, 184) to a combustor-facing side (142) of the combustor shell (104, 184). The combustor shell (104, 184) may include a spacer (146) comprising a first segment (265) coupled to a first flange (260), wherein the first flange (260) is disposed on the diffuser-facing side (141) of the combustor shell (104, 184), wherein an outer wall (348) of the spacer (146) is coupled with at least a portion of an inner wall (149) of the combustor shell (104, 184).