CMC Gas Turbine Component with Separated Fiber Plies
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Solution Overview
Problem
Implementing ceramic matrix composite (CMC) materials in gas turbine engine airfoils poses challenges due to unique thermal and interlaminar stress issues, which affect the component's durability and resistance to thermal gradients.
Innovation Solution
A CMC gas turbine engine component with separated fiber plies and void pockets is designed to reduce thermal gradients and interlaminar stresses. The void pockets act as insulation regions and allow for unconstrained local thermal growth of the fiber plies, thereby reducing interlaminar tension and facilitating damage tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If CMC materials are used in airfoils to achieve high temperature resistance, then temperature capability is improved, but thermal gradients and interlaminar stresses increase
Solution Approach 1:
The patent introduces a porous foam core material between fiber plies in the CMC airfoil structure. This porous material acts as a thermal buffer that reduces thermal gradients through its low thermal conductivity, while also accommodating thermal expansion differences between layers, thereby reducing interlaminar stresses and improving damage tolerance.
2Temperature
If CMC materials are used in airfoils to achieve high temperature resistance, then temperature capability is improved, but durability decreases due to thermal gradients
Solution Approach 1:
The porous foam core material serves as a thermal buffer that reduces thermal gradients through its low thermal conductivity, thereby reducing thermal stress and improving the durability and reliability of the CMC airfoil under high temperature conditions.
Solution Approach 2:
The patent creates a composite structure combining fiber plies with a porous foam core material. This composite design leverages the high temperature resistance of CMC fibers while the porous foam provides thermal buffering, achieving both temperature capability and durability.
3Strength
If fiber plies are stacked contiguously to maintain structural integrity, then strength is improved, but thermal gradient resistance worsens
Solution Approach 1:
The porous foam material is positioned between fiber plies to act as a thermal buffer. This maintains the structural integrity provided by contiguous fiber stacking while introducing thermal resistance to reduce thermal gradients, resolving the contradiction between strength and thermal gradient resistance.
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 reduces thermal gradients and interlaminar stresses, enhancing the durability and damage tolerance of CMC airfoils in gas turbine engines. The void pockets provide insulation and allow for local thermal growth, mitigating the risks of thermal damage and improving the overall performance of the engine components.
Implementation Method 1
The void pockets act as insulation regions and allow for unconstrained local thermal growth of the fiber plies
Implementation Method 2
The void pockets act as insulation regions and allow for unconstrained local thermal growth of the fiber plies, thereby reducing interlaminar tension
Data Source
Figure 1~2
AI summary
A gas turbine engine component (60) includes a component wall (62) that has an exterior core gaspath side (64a) and an opposed interior side (64b). The component wall (62) is formed of a ceramic matrix composite that includes a plurality of fiber plies (66) disposed in a ceramic matrix. The component wall (62) includes a corner (68a) that connects first and second wall sections (68b, 68c). The fiber plies (66) extend continuously through the first wall section (68b), the corner (68a), and the second wall section (68c). The fiber plies (66) are in a stacked contiguous arrangement in the first and second wall sections (68b, 68c) and at least some of the fiber plies (66) separate from one another in the corner (68a) to define one or more void pockets (70) therebetween.