Gas Turbine Rotor Airfoil with Active Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine rotor assemblies face challenges in effectively managing vibration and structural integrity, particularly in withstanding centrifugal loads and foreign object debris impacts, while maintaining aerodynamic efficiency and durability.
Innovation Solution
The rotor assembly incorporates a hybrid airfoil design with a metallic sheath and composite core, featuring retention pins and resilient support members that allow for flexibility and damping, along with adjustable damping elements and shrouds to control vibration and loads, and a platform system that secures airfoils and opposes movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the airfoil structure is made rigid to withstand centrifugal loads and impacts, then structural strength is improved, but vibration and stress increase reducing durability
Solution Approach 1:
The airfoil structure incorporates dynamic characteristics by allowing controlled flexibility through the composite core and damping elements. The structure transitions from a purely rigid design to one that can dynamically absorb and dissipate vibration energies while maintaining structural integrity under centrifugal loads and impact conditions.
Solution Approach 2:
The airfoil employs a composite structure with a metallic sheath providing strength and a composite core providing flexibility and damping. This composite material approach allows the structure to simultaneously achieve high strength-to-weight ratio and vibration damping capabilities, resolving the contradiction between strength and durability.
2Reliability
If damping elements are added to control vibration, then durability is improved, but device complexity increases
Solution Approach 1:
The damping elements are integrated within the airfoil structure itself, merging the damping function with the structural components. The composite core and metallic sheath work together as both structural and damping elements, eliminating the need for separate external damping systems and reducing overall device complexity.
Solution Approach 2:
The airfoil structure provides its own damping capability through the inherent properties of the composite core and the interaction between core and sheath. The structure serves dual purposes: maintaining structural integrity and actively damping vibrations, thereby eliminating the need for additional dedicated damping components.
3Reliability
If the airfoil is allowed to flex and twist to reduce impact damage, then durability is improved, but aerodynamic efficiency may deteriorate
Solution Approach 1:
The airfoil structure implements local quality by providing flexibility specifically in regions subjected to impact loads while maintaining rigidity in aerodynamically critical areas. The composite core allows controlled flexing at the root and trailing edge where impacts occur, while the metallic sheath maintains the aerodynamic contour and surface quality for efficient flow passage.
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 design enhances the durability and aerodynamic efficiency of the rotor assembly by allowing airfoils to flex and twist, reducing the risk of damage from impacts, and actively controlling vibration through adjustable damping elements, thereby improving the overall performance and reliability of the gas turbine engine.
Implementation Method 1
Each damping element is operable to selectively cause adjacent portions of the airfoil section to stiffen in response to a predefined control signal
Implementation Method 2
resilient support members that allow for flexibility and damping
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An airfoil (66, 166, 266, 366, 466, 566, 566', 666, 766) for a gas turbine engine (20) includes an airfoil section (66A, 166A, 266A, 366A, 466A, 566A, 666A, 766A) that extends from a root section (66B, 266B, 366B, 466B, 566B, 666B, 766B). The airfoil section (66A... 766A) extends between a leading edge (LE) and a trailing edge (TE) in a chordwise direction (C) and extends between a tip portion (66C, 266C, 466C, 766C) and the root section (66B...766B) in a radial direction (R). The airfoil section (66A... 766A) defines a pressure side (P) and a suction side (S) separated in a thickness direction (T), and the airfoil section (66A...766A) includes a metallic sheath (72, 172, 272, 372, 472, 572, 672) that defines an internal cavity receiving a composite core (74, 174, 274, 474, 574, 774). The root section (66B...766B) defines at least one bore (85, 485) dimensioned to receive a retention pin (68, 168, 368, 468, 568, 668). At least one damping element (487, 487', 587, 587', 687, 787) is received in the internal cavity and that selectively causes the airfoil section (66A...766A) to stiffen.