Guide Blade Ring Damping Pockets for Turbomachine Resonance Control
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Solution Overview
Problem
Turbomachines with guide blades designed as single blades exhibit reduced damping, leading to stronger resonances and higher natural oscillation amplitudes, which can cause material stresses and poorer fatigue strength.
Innovation Solution
A blade arrangement with guide blade elements connected by damping elements that dissipate oscillation energy through friction, using additive manufacturing to create hook sections and pockets for damping elements like corrugated metal sheets or wire-shaped designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If guide blades are designed as single blades, then manufacturing is simple and assembly is easy, but damping behavior is poor leading to stronger resonances and higher natural oscillation amplitudes
Solution Approach 1:
The guide blade is divided into multiple airfoils (at least two) that are arranged side by side and connected to form a single guide blade element. This segmentation allows the structure to maintain manufacturing simplicity while improving damping behavior through the interaction of multiple airfoil components.
Solution Approach 2:
Multiple airfoils are merged into a single guide blade element structure, combining their damping characteristics to achieve superior overall damping behavior while maintaining the simplicity of a unified component design.
2Reliability
If guide blades are designed as multiple airfoils per element, then damping behavior improves, but manufacturing complexity increases
Solution Approach 1:
Multiple airfoils are merged into a single integrated guide blade element, combining their damping characteristics to achieve superior overall damping behavior while maintaining the simplicity of a unified component design.
Solution Approach 2:
The guide blade element structure serves multiple functions simultaneously: it guides the flow, provides damping through multiple airfoils, and maintains structural integrity as a single component, reducing the need for separate damping elements.
3Reliability
If multiple guide blade elements are used, then damping is improved, but assembly complexity and gap sealing requirements increase
Solution Approach 1:
The guide blade ring is segmented into multiple guide blade elements arranged in the circumferential direction, with each element providing independent damping capability while contributing to the overall system performance.
Solution Approach 2:
A damping element is introduced as an intermediary component that connects adjacent guide blade elements in the circumferential direction, providing additional damping while simplifying the assembly process and ensuring proper gap sealing.
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
Improves resonance behavior and natural oscillation damping, enhancing fatigue strength and operational stability while allowing cost-effective manufacturing.
Implementation Method 1
provides damping or friction of the damping element at the guide blade elements in order to dissipate oscillation energy of a natural oscillation
Data Source
AI summary
A blade arrangement for a thermal turbomachine through which axial flow may pass, including a guide blade ring having at least two guide blade elements situated along a circumferential direction of the turbomachine. Each guide blade element of the at least two guide blade elements includes at least one airfoil, which at its radially outer end includes a platform that is connected in one piece to the at least one airfoil. At least one hook section at its radially outer side protrudes from the platform in the radial direction. The at least one hook section in the radial direction forms a pocket of the guide blade element that is delimited by the at least one hook section, the guide blade element, and the platform, and that is open at one side in the axial direction of the turbomachine. The blade arrangement further includes at least one damping element that is situated in the pocket and connects at least two neighboring guide blade elements in the circumferential direction.