Combustor Liner Bushing Joint for Thermal Expansion Relief
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Solution Overview
Problem
Bolted joints in gas turbine engines limit axial and radial movement of combustor components due to thermal expansion and contraction, leading to potential mechanical stress and inefficiencies.
Innovation Solution
A connection system using bushing bolts with sliding engagement between CMC liner flanges and connector heads allows for radial movement, incorporating thermal activation openings to manage temperature changes and reduce weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If bolted joints are used to connect combustor components, then structural strength and rigidity are improved, but thermal expansion and contraction are constrained leading to mechanical stress
Solution Approach 1:
The connection system transitions from a static rigid bolted joint to a dynamic system that accommodates thermal movement. The bushing bolt assembly allows the CMC liner to expand and contract radially during thermal cycles while maintaining structural connection, converting the constrained static system into an adaptive dynamic system that responds to thermal conditions.
Solution Approach 2:
The invention changes the connection parameters by introducing a bushing interface between the bolt and CMC liner flange. This bushing allows relative movement and changes the mechanical constraints, enabling thermal expansion while maintaining structural integrity. The connection geometry is modified to permit controlled movement rather than rigid fixation.
2Stability of the object's composition
If rigid bolted connections are used, then structural stability is improved, but thermal expansion freedom is reduced causing inefficiencies
Solution Approach 1:
The bushing acts as an intermediary element between the bolted connection and the CMC liner flange. This intermediate component mediates the interaction between structural stability requirements and thermal expansion needs, allowing the system to maintain both rigidity for structural support and flexibility for thermal movement accommodation.
3Ease of manufacture
If traditional bolted joints are used, then manufacturing simplicity is maintained, but thermal management efficiency is reduced
Solution Approach 1:
The connection system is segmented into distinct functional components: the bushing bolt, the bushing interface, and the CMC liner flange. This segmentation allows each component to be optimized for its specific function while maintaining overall manufacturing feasibility. The modular approach enables thermal management capabilities without requiring complete redesign of the entire connection system.
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
Enables efficient thermal management and reduced mechanical stress by allowing components to expand and contract freely, improving the durability and performance of the combustor.
Implementation Method 1
allows the CMC liner and the dome structure to have radial movement... thermal activation openings that provide airflow through the bushing bolt so as to further the cooling (or heating) of the bushing bolt
Data Source
AI summary
A combustor for a gas turbine engine includes a dome structure having an outer dome connecting flange, a cowl structure, an outer liner having an outer liner connecting flange, and an inner liner having an inner liner connecting flange. At least one of (a) the outer liner connecting flange includes a bushing having an opening therethrough, or (b) the outer dome connecting flange includes a bushing having an opening therethrough. The outer dome connecting flange, the cowl structure, and the outer liner are connected together via an outer connection that includes an outer connecting member having a head and a shank. An outer surface of the head slidingly engages with at least one of (i) an inner surface of the opening of the bushing in the outer liner connecting flange, or (ii) an inner surface of the bushing in the outer dome connecting flange.