Contoured Endwall Composite Platform for Gas Turbine Airfoils
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Developing materials for turbine blades and vanes that are heat-resistant and lightweight to reduce cooling demands and enhance propulsive efficiencies in gas turbine engines, while also addressing the challenge of attaching contoured composite platforms onto airfoil members.
Innovation Solution
The use of ceramic matrix composite (CMC) or organic matrix composite (OMC) materials for airfoil members and platforms, with the platform featuring a contoured endwall designed to optimize aerodynamic performance by reducing endwall losses due to horseshoe vortexing, and a method of forming these assemblies using chopped composite fibers infiltrated with a matrix material and bonding techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ceramic matrix composite (CMC) or organic matrix composite (OMC) materials are used for airfoil members and platforms, then heat resistance and lightweight characteristics are improved, but attachment difficulty increases
Solution Approach 1:
The platform is pre-formed with a contoured endwall geometry that facilitates attachment to the airfoil member. The contouring is designed in advance to match the airfoil root geometry, enabling easier bonding or mechanical attachment while maintaining the heat-resistant composite material structure.
Solution Approach 2:
The endwall of the platform is given a specific contoured shape with defined geometric parameters (curvature, thickness distribution) that optimize both aerodynamic performance and attachment characteristics. This parameter optimization resolves the contradiction by making the composite platform easier to attach while maintaining heat resistance.
2Loss of energy
If a contoured endwall is provided on the composite platform, then aerodynamic performance is improved by reducing endwall losses, but manufacturing complexity increases
Solution Approach 1:
The platform is manufactured as a composite material structure (CMC or OMC) that can be formed into complex contoured shapes through molding or additive manufacturing techniques. The composite material properties enable the creation of the contoured endwall geometry without significantly increasing manufacturing complexity, as the material can be shaped in its pre-form or matrix phase before final curing.
Solution Approach 2:
The endwall is designed with smooth curved contours rather than sharp edges or flat surfaces. This curvature reduces horseshoe vortexing and endwall losses while being manufacturable using composite molding techniques, where curved surfaces are naturally accommodated by the forming process.
3Weight of moving object
If composite materials are used for platforms, then weight is reduced improving propulsive efficiency, but structural strength for attachment decreases
Solution Approach 1:
The platform exhibits local quality variations in its structure - the endwall region has optimized thickness and contouring for aerodynamic performance and attachment, while other regions maintain sufficient structural strength. The composite material allows different areas to have different properties tailored to their specific functions, resolving the contradiction between weight reduction and attachment strength.
Solution Approach 2:
The use of ceramic matrix composite or organic matrix composite materials provides high specific strength (strength-to-weight ratio). These composite materials inherently offer both the weight reduction needed for propulsive efficiency and the structural strength required for reliable attachment to the airfoil member.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An airfoil member and platform assembly for a gas turbine engine is provided. The platform to which the airfoil member is anchored is made of a composite material and includes an endwall defining a contoured region for improved aerodynamics. The contoured region influences the flow of gases through the flow passages between the airfoil members, thereby reducing endwall losses due to horseshoe vortexing. The composite material may be woven ceramic matrix composite fibers infiltrated with a ceramic matrix material or woven organic matrix composite fibers infiltrated with an organic matrix material.