Non-Uniform Thermal Coating for CMC Engine Components
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As gas turbine engine operating temperatures increase, ceramic matrix composite (CMC) components face thermal stresses due to high thermal gradients between their interior and exterior surfaces, leading to potential damage, as conventional cooling methods exacerbate these stresses.
Innovation Solution
A non-uniform thermal coating with a lower thermal conductivity than the CMC substrate is applied to the inner surface of hot gas path components, allowing for tailored thermal gradient management and reduced thermal stresses by regulating heat transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling methods (cooling circuits/holes) are introduced to CMC components, then cooling effectiveness is improved, but thermal gradient between interior and exterior surfaces increases leading to thermal stress damage
Solution Approach 1:
The patent applies a non-uniform thermal coating distribution on the interior surface of CMC components, where the coating density or thickness varies in different regions. This creates locally differentiated thermal insulation properties that reduce thermal gradients at critical areas without compromising overall cooling effectiveness, thereby resolving the contradiction between cooling performance and thermal stress resistance.
Solution Approach 2:
The patent modifies the thermal conductivity parameter of the coating material or the geometric parameters (thickness, distribution pattern) of the thermal coating to optimize heat transfer characteristics. By adjusting these parameters, the coating can provide appropriate thermal resistance in different regions, reducing thermal stresses while maintaining effective cooling.
2Productivity
If higher operating temperatures are used to increase efficiency and thrust-to-weight ratio, then engine performance is improved, but material temperature limits are exceeded requiring new materials or cooling methods
Solution Approach 1:
The patent introduces a thermal coating as an intermediary layer between the hot gas path environment and the CMC component substrate. This coating acts as a thermal mediator that regulates heat transfer, allowing the component to withstand higher operating temperatures without exceeding material limits, thereby enabling improved engine performance while protecting the substrate material.
Solution Approach 2:
The patent employs a composite structure consisting of the CMC substrate combined with a thermal coating layer. This composite material system combines the high-temperature capability of CMC with the thermal insulation properties of the coating, creating a multi-functional material solution that enables higher operating temperatures for improved engine efficiency and thrust-to-weight ratio.
3Ease of manufacture
If a uniform thermal coating is applied to the inner surface, then manufacturing simplicity is maintained, but thermal gradient management cannot be tailored to specific cooling requirements
Solution Approach 1:
The patent implements a non-uniform thermal coating distribution on the interior surface, where the coating's thickness, density, or composition varies across different regions. This allows the thermal gradient to be tailored to specific cooling requirements of different areas, improving adaptability while the coating application process remains based on established techniques.
Solution Approach 2:
The patent creates a dynamic or variable thermal coating structure that can be adjusted or optimized for different operational conditions or component regions. This variability enables the thermal management system to adapt to specific cooling requirements without fundamentally changing the manufacturing approach, balancing ease of manufacture with adaptability.
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 thermal coating effectively reduces thermal gradients and manages thermal stresses, enhancing the durability and performance of CMC components in high-temperature environments without compromising cooling effectiveness.
Implementation Method 1
The thermal coating may be applied to the inner surface so as to have a non-uniform distribution along at least a portion of the inner surface, wherein the non-uniform distribution provides for change in a thermal gradient experienced across the hot gas path component
Data Source
AI summary
A hot gas path component for an engine may generally include a substrate extending between an outer surface and an inner surface opposite the outer surface. The outer surface may be configured to be exposed to a hot gas path of the engine. In addition, the substrate may be formed from a non-metallic composite material. The hot gas path component may also include a thermal coating disposed on the inner surface of the substrate. The thermal coating may be applied to the inner surface so as to have a non-uniform distribution along at least a portion of the inner surface, wherein the non-uniform distribution provides for change in a thermal gradient experienced across the hot gas path component between the outer and inner surfaces of the substrate.