Guide Vane Assembly With Friction Damping for Resonance Control
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Solution Overview
Problem
Turbomachinery guide vanes with multi-blade designs exhibit reduced damping characteristics, leading to stronger resonances, higher natural vibrations, material stresses, and reduced fatigue strength, which are detrimental to operational durability.
Innovation Solution
A blade arrangement with a damping element that connects guide vane elements circumferentially, dissipating vibrational energy through friction, utilizing integrally connected platforms and hook sections to form pockets for damping elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If guide vanes are constructed as multi-blade elements, then manufacturing advantages are achieved, but damping characteristics are reduced leading to stronger resonances and higher natural vibrations
Solution Approach 1:
The guide vane is divided into multiple individual blade elements (first guide vane element, second guide vane element, etc.) arranged circumferentially. Each element can be manufactured separately and then assembled, combining the manufacturing advantages of modular construction with the damping benefits of discrete elements that can move independently to dissipate vibrational energy.
Solution Approach 2:
A damping element is introduced as an intermediary component between adjacent guide vane elements. This damping element provides controlled frictional interaction that dissipates vibrational energy while allowing the elements to maintain their structural integrity and manufacturing advantages. The damping element acts as a mediator that converts the harmful vibrations into useful energy dissipation through friction.
2Ease of manufacture
If guide vanes are constructed as multi-blade elements, then manufacturing advantages are achieved, but material stresses and reduced fatigue strength occur due to stronger resonances
Solution Approach 1:
By segmenting the guide vane into multiple independent blade elements, the structure allows each element to respond independently to vibrational loads. This segmentation, combined with the damping elements, reduces the transmission of stress waves through the structure, thereby lowering material stresses and improving fatigue strength while maintaining manufacturing advantages.
Solution Approach 2:
The damping element serves as an intermediary that reduces the transmission of vibrational energy and stress between adjacent guide vane elements. Through controlled friction, it dissipates energy that would otherwise propagate as damaging stress waves, thereby reducing material stresses and improving fatigue strength.
3Ease of manufacture
If guide vanes are constructed as multi-blade elements, then manufacturing advantages are achieved, but operational durability is reduced due to higher amplitudes of natural vibrations
Solution Approach 1:
The guide vane is segmented into multiple blade elements that can move independently. This segmentation allows each element to dissipate vibrational energy through controlled movement against damping elements, reducing the amplitudes of natural vibrations and thereby improving operational durability while maintaining manufacturing advantages.
Solution Approach 2:
The damping element acts as an intermediary that provides controlled frictional resistance between adjacent guide vane elements. This friction dissipates vibrational energy, reducing the amplitudes of natural vibrations and preventing the development of high-cycle fatigue, thus improving operational durability.
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, natural vibration damping, and manufacturability, reducing material stresses and enhancing operational durability by dissipating vibrational energy through friction.
Implementation Method 1
provides damping or friction of the damping element on the guide vane elements in order to dissipate vibrational energy from a natural oscillation
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
A blade assembly for an axially flowing thermal turbomachine comprises a guide vane ring with at least two guide vane elements 10 arranged along a circumferential direction U of the turbomachine. Each of the at least two guide vane elements 10 has at least one blade 22, which at its radially outer end comprises a platform 12 integrally connected to the at least one blade 22. At least one hook section 14 projects radially from the radially outer side of the platform 12. The at least one hook section 14 forms a pocket 24 of the guide vane element 10 in the radial direction. The pocket 24 is bounded by the at least one hook section 14, the guide vane element 10, and the platform 12. The pocket 24 is open on one side in the axial direction of the turbomachine. The blade assembly includes at least one damping element 20.The damping element 20 is arranged in the pocket 24 and connects at least two adjacent guide vane elements 10 in the circumferential direction U. An axially flowable thermal turbomachine comprises the blade arrangement.