Axial Turbine Rotor Vane Attenuator for Dynamic Stress Damping
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Solution Overview
Problem
Existing rotor vane assemblies face challenges with vibration damping, assembly interference, and sensitivity to dynamic excitations, with current methods providing inadequate damping effectiveness and complicating the assembly process.
Innovation Solution
A rotor stage with a vibration attenuator featuring active and reactive surfaces that contact rest elements of subsequent vanes, forming an extended contact surface to dampen vibrations and adjust natural frequencies, while being designed for easy assembly and made of materials like plastic to enhance damping, such as fiberglass or carbon fiber composites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration dampening devices are added to rotor vanes, then vibration damping effectiveness is improved, but device complexity and assembly difficulty increase
Solution Approach 1:
The attenuator is divided into two separable portions (first and second portions) that can be assembled independently and then connected. This segmentation allows each portion to be installed on adjacent vanes without interference from the other side, simplifying the assembly process while maintaining effective vibration damping through the combined structure.
Solution Approach 2:
The attenuator acts as an intermediary element positioned between adjacent rotor vanes, mediating the interaction between them. By introducing this intermediate component with specific contact surfaces, the system achieves vibration damping without requiring direct modification of the vane structures themselves, thus maintaining simplicity.
2Reliability
If connecting elements protrude from vanes to contact adjacent vanes, then vibration dampening is achieved, but assembly interference occurs requiring mechanical spreaders
Solution Approach 1:
By separating the attenuator into two portions that face opposite directions, each portion can be installed on its respective vane without interfering with the installation on the adjacent vane. This eliminates the need for mechanical spreaders during assembly while maintaining the contact mechanism for vibration dampening.
Solution Approach 2:
Instead of having single-sided connecting elements that protrude from one vane, the invention uses two-sided attenuator portions that protrude from adjacent vanes in opposite directions. This inverted approach allows both sides to be installed simultaneously without interference, reversing the traditional single-sided connection method.
3Reliability
If attenuators are made with extended contact surfaces, then vibration damping effectiveness is improved, but manufacturing complexity increases
Solution Approach 1:
The extended contact surface requirement is divided into two separate portions, each with its own contact surface. This segmentation allows each portion to be manufactured with a simpler single contact surface rather than requiring a complex multi-surface geometry, reducing manufacturing complexity while maintaining the total extended contact area for effective vibration damping.
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
The attenuator effectively dampens vibrations, simplifies the assembly process, and increases the rotor stage's resistance to low-frequency dynamic excitations by stiffening the assembly and adjusting natural frequencies, thereby enhancing the rotor's stability and vibration resistance.
Implementation Method 1
The attenuator has a first active surface adapted to contact a first reactive surface belonging to a first rest element and a second active surface adapted to contact a second reactive surface belonging to a second rest element
Implementation Method 2
When the rotor is moving, due to the centrifugal force, such connecting elements tend to tilt outwards and the vanes tend to extend
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
Rotor stage of an axial turbine comprising a plurality of vanes and a plurality of attenuators interposed between each pair of subsequent vanes, said attenuator impeding the rotation of the vane profiles caused by the centrifugal force during the operation and achieving a stiffening of the rotor vane array.