Detuned Vane Airfoil Assembly Using Composite Material Variations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine stator vanes face challenges in managing vibrations across a broad range of natural resonances and mode frequencies, leading to potential fatigue and reduced service life due to the differences in vibration characteristics between rotor and stator stages, particularly in unshrouded rotor blades and shrouded stator vanes.
Innovation Solution
The use of organic matrix composite materials with different fiber and matrix compositions for adjacent airfoils, ensuring distinct vibration frequencies that are separated by more than the full width at half maximum, thereby detuning the vibration response and increasing damping capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If identical composite materials are used for all airfoils, then manufacturing consistency and structural uniformity are improved, but vibration fatigue increases due to resonant coupling across adjacent airfoils
Solution Approach 1:
The patent applies local quality by varying the composite material properties (fiber type, matrix composition, or layup configuration) in specific local regions - namely, alternating between different composite material formulations for adjacent airfoils. This local differentiation detunes the vibration frequencies of neighboring airfoils, preventing resonant coupling and reducing vibration fatigue while maintaining manufacturing consistency through standardized material selection protocols.
2Reliability
If different composite materials are used for adjacent airfoils, then vibration frequencies are detuned and damping is increased, but manufacturing complexity increases
Solution Approach 1:
The patent implements parameter changes by systematically varying key material parameters (such as fiber orientation angles, matrix resin type, or fiber-to-resin ratio) between adjacent airfoils. These controlled parameter changes shift the natural vibration frequencies of individual airfoils out of phase with their neighbors, achieving vibration detuning and enhanced damping. The changes are applied in a predictable, alternating pattern that simplifies manufacturing planning while effectively breaking up vibration resonance across the airfoil array.
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
This approach effectively reduces vibration fatigue and increases the service life of gas turbine engine stator vanes by absorbing vibration energy and allowing for a wider range of airfoil geometries and designs, improving loading and flow turning characteristics.
Implementation Method 1
different composite materials are selected for adjacent airfoils, to define a vibration mode with different vibration frequencies in the circumferentially adjacent airfoils, the different vibration frequencies being separated by more than a full width of the vibration mode at half maximum
Implementation Method 2
absorbing vibration energy and allowing for a wider range of airfoil geometries and designs
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A vane assembly (40) comprises circumferentially adjacent airfoils (42A,42B) formed of composite materials. The airfoils (42A,42B) have matching exterior geometries defined by pressure and suction surfaces (43,44) extending axially from a leading edge (45) to a trailing edge (46) and radially from a root section (47) to a tip section (48). An inner platform (50) is attached to each of the circumferentially adjacent airfoils (42A,42B) at the root section (47), and an outer platform (51) is attached at the tip section (48). The composite materials are selected to define a vibration mode (H1,H2,H3,H1',H2',H3') with different vibration frequencies in the circumferentially adjacent airfoils (42A,42B), where the different vibration frequencies are separated by more than a full width of the vibration mode at half maximum (FWHM).