Ceramic Vane Arc Segments with Monolithic Support Rings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Implementing ceramic materials in gas turbine engine airfoils is challenging due to lower material stress limits, which existing support schemes fail to address effectively, leading to stress and leakage issues.
Innovation Solution
The use of monolithic ceramic matrix composite (CMC) support rings and vane arc segments with integrated retainers and flanges that provide low-stress support and fluid isolation, reducing leakage and thermal mismatch, while maintaining aerodynamic efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ceramic materials are used in airfoils to achieve high temperature resistance, then temperature capability is improved, but material stress limits are exceeded leading to support scheme failure
Solution Approach 1:
The airfoil is divided into multiple segments (first airfoil segment, second airfoil segment, etc.) that can be independently supported by separate support rings. This segmentation allows each segment to be optimally supported without overloading any single support structure, resolving the contradiction between high temperature resistance and material stress limits.
Solution Approach 2:
Support rings are introduced as intermediary components between the ceramic airfoil segments and the turbine housing. These support rings distribute mechanical loads and provide structural reinforcement, enabling the ceramic airfoils to operate at high temperatures without exceeding their stress limits.
2Strength
If existing support schemes are used for ceramic airfoils, then structural support is provided, but leakage occurs between airfoil segments
Solution Approach 1:
The support rings are designed to perform multiple functions simultaneously: they provide structural support for the airfoil segments and act as sealing surfaces to prevent gas leakage. By merging support and sealing functions into a single integrated component, the design eliminates leakage while maintaining structural integrity.
Solution Approach 2:
Flexible sealing elements or thin film barriers are incorporated at the interfaces between airfoil segments and support rings. These flexible sealing components conform to thermal expansion and contraction, maintaining seal integrity under varying operating conditions while preventing gas leakage.
3Strength
If traditional support structures are used, then mechanical support is provided, but thermal mismatch causes stress concentration
Solution Approach 1:
The support rings are designed with specific material properties and geometric parameters that match the thermal expansion characteristics of the ceramic airfoil segments. By carefully selecting material parameters and cross-sectional dimensions, the support rings minimize thermal mismatch stresses while providing the required mechanical support.
Solution Approach 2:
The support rings may be constructed from composite materials that combine high-temperature resistance with appropriate thermal expansion properties. This allows the support structure to accommodate thermal growth of the ceramic airfoils without creating excessive stress concentration, while still providing effective mechanical support.
Data Source
AI summary
A turbine section for a gas turbine engine includes inner and outer diameter ceramic matrix composite (CMC) support rings that define a gaspath there between. Each of the inner and outer diameter CMC support rings are monolithic and continuous. CMC vane arc segments are disposed in the gaspath and supported by the inner and outer diameter CMC support rings. Each of the CMC vane arc segments includes inner and outer platforms and an airfoil section there between. At least one retainer engages the inner or outer diameter CMC support rings with the CMC vane arc segments to retain the CMC vane arc segments between the inner and outer diameter CMC support rings.