Gas Turbine Composite Vane Trailing Edge Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in gas turbine engine design is to maintain a small trailing edge radius for aerodynamic performance while preventing the trailing edge of composite mid-turbine frame airfoils from bulging open and splitting due to differential pressure, which is difficult with continuous layers of composite materials.
Innovation Solution
The airfoil structure features a V-shaped trailing edge with a filler between layers, constructed from ceramic matrix composite materials like silicon carbide, and includes a single cavity to accommodate components, with varying thickness and transitional plies to reinforce stress areas and prevent splitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a continuous layer of composite plies is used at the trailing edge, then manufacturing is simplified, but the trailing edge cannot achieve a small radius and will bulge open under differential pressure
Solution Approach 1:
The trailing edge plies are segmented into multiple discrete plies (first trailing edge ply, second trailing edge ply, third trailing edge ply) rather than using a continuous layer. These segmented plies can be joined at the trailing edge to form the desired small radius shape while accommodating the differential pressure loads without bulging open.
Solution Approach 2:
The plies are configured with different local properties - the first trailing edge ply has a first thickness, the second trailing edge ply has a second thickness, and they are joined at specific locations. This local variation in ply configuration allows the trailing edge to achieve both the small radius shape and the structural integrity needed to resist bulging under pressure.
2Shape
If plies are joined at the trailing edge to achieve small radius, then aerodynamic performance is improved, but the trailing edge is prone to splitting under differential pressure
Solution Approach 1:
The airfoil utilizes composite material construction with multiple layers of plies (including leading edge plies, trailing edge plies, and intermediate plies) that are bonded together. This composite structure provides both the small trailing edge radius shape and the enhanced strength to resist splitting under differential pressure between the interior and exterior of the airfoil wall.
Solution Approach 2:
The airfoil structure employs nested layers of plies where inner plies and outer plies are arranged in concentric configurations. The trailing edge plies are nested between leading edge plies and intermediate plies, creating a layered composite structure that reinforces the trailing edge against splitting while maintaining the small radius geometry.
3Adaptability or versatility
If component passages are provided through the airfoil, then functionality is improved, but the differential pressure causes trailing edge bulging and splitting
Solution Approach 1:
The airfoil structure is designed with pre-configured trailing edge ply arrangements and thickness variations before the airfoil is subjected to operational differential pressure. The plies are joined and configured in advance to anticipate and resist the bulging and splitting forces that will occur when components pass through the airfoil under differential pressure conditions.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An airfoil for a gas turbine engine has a first layer forming a cavity having transitioning from a first thickness to a second thickness through a ply drop region. A second layer is secured to the first layer.