Ceramic Brush Seal Structure for High-Temperature Gas Turbines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current metallic brush seals in gas turbine engines experience high thermal signature, severe creep, and oxidation at operating temperatures, necessitating improved engine component seals and manufacturing methods.
Innovation Solution
A ceramic seal system comprising a structural body portion with oxide/oxide woven ceramic fiber stacked plies and a flexible edge seal formed by oxide ceramic fibers extending from the body, which is less infiltrated with ceramic matrix slurry, allowing for a more flexible and durable seal component that can withstand high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metallic brush seals are used in gas turbine engines, then sealing function is provided, but high thermal signature, severe creep and oxidation occur at operating temperatures
Solution Approach 1:
The patent changes the material parameters from metallic to ceramic composition, specifically using oxide ceramic fibers (such as alumina, silica, magnesia) to fundamentally alter the thermal and chemical properties of the seal component, enabling it to withstand high temperatures without creep and oxidation
Solution Approach 2:
The patent employs composite material structure consisting of oxide ceramic fibers embedded in a binder matrix, creating a ceramic brush seal that combines the high-temperature resistance of ceramic fibers with the binding properties of the matrix material, achieving both durability and sealing functionality
2Strength
If ceramic seal component with uniform infiltration is used, then structural strength is improved, but flexibility of the seal edge is reduced
Solution Approach 1:
The patent applies local quality by creating non-uniform infiltration where the binder material selectively infiltrates the structural body portion while leaving the seal edge region with minimal or no infiltration, allowing different regions of the same component to have different properties: the structural body gains strength while the seal edge maintains flexibility
Solution Approach 2:
The patent uses partial infiltration action where the binder slurry is applied in a controlled manner to achieve infiltration only in specific zones (the structural body) while deliberately avoiding complete infiltration of the entire component, particularly preserving the flexibility-critical seal edge region
Data Source
Figure 1
Figure 2~3
Figure 2A
AI summary
A ceramic brush seal for a gas turbine engine and a process for manufacturing the seal are provided. In one example, the process includes deinfiltrating an edge of a plurality of plies having a preimpregnated configuration. The edge is defined by a plurality of ceramic fibers extending away from a portion edge of a matrix infiltrated portion of each of the plies. In another example, the process includes masking an edge of a plurality of plies, the edge being defined by a plurality of ceramic fibers extending away from a portion edge of a body portion of each of the plies, and infiltrating the body portion of the plurality of plies with a ceramic matrix slurry. The plies are stacked, formed into a green body and then fired to form the component. The plies may include oxide/oxide woven ceramic fiber plies.