Tuned Ring Dampers for Integrally Bladed Rotor Vibration
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Solution Overview
Problem
Current damping solutions for integrally bladed rotors (IBRs) are ineffective in reducing vibration amplitudes due to low damping and mistuning, particularly in blade-dominated modes, as they require significant relative motion between the damper and the rotor, which is challenging to achieve, and are not robust across multiple operation regimes and frequency ranges.
Innovation Solution
A tuned vibration absorber concept is introduced, where the damper is designed to have a natural frequency matching that of the targeted IBR mode, enabling frictional dissipation and increased damper motion, thereby reducing the need for placement at high-motion locations and enhancing effectiveness for blade-dominated modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional ring dampers are used, then damping is provided through friction, but significant relative motion between the damper and rotor is required which is challenging to achieve and limits effectiveness
Solution Approach 1:
The damper is designed with dynamic characteristics that allow it to resonate at the target frequency, converting the static friction requirement into a dynamic resonance-based energy dissipation mechanism. This enables the damper to achieve significant relative motion through resonance rather than requiring large-amplitude forced motion.
Solution Approach 2:
The invention utilizes mechanical vibration and resonance principles by tuning the damper's natural frequency to match the target rotor mode frequency. This resonance amplifies the relative motion between the damper and rotor, enabling effective friction-based energy dissipation without requiring the damper to be placed at high-motion locations.
2Loss of energy
If dampers are placed at high-motion locations to achieve relative motion, then frictional dissipation increases, but placement constraints and stress concentrations are introduced
Solution Approach 1:
By designing the damper with specific dynamic characteristics and tuning its natural frequency, the invention enables the damper to generate sufficient relative motion through resonance even when placed at locations with lower structural motion. This eliminates the need to place dampers at high-motion locations, reducing placement constraints and avoiding stress concentration issues.
3Reliability
If conventional dampers are used, then damping effectiveness is limited, but the solution is not robust across multiple operation regimes and frequency ranges
Solution Approach 1:
The invention employs tunable parameters including the damper's natural frequency, mass, and stiffness characteristics. By adjusting these parameters, the damper can be optimized for specific target frequencies and operation regimes, providing both high damping effectiveness and adaptability across multiple operating conditions.
Solution Approach 2:
The damper design incorporates features that enable it to function effectively across multiple operation regimes and frequency ranges. The tunable characteristics allow a single damper design to address multiple vibration modes and operating conditions, providing universal applicability rather than requiring separate dampers for each regime.
4Reliability
If mistuning occurs in IBRs, then vibration localization increases, but conventional dampers cannot effectively address blade-dominated modes
Solution Approach 1:
The invention uses resonance-based vibration principles where the damper is tuned to match the target blade-dominated mode frequency. This resonance amplifies the interaction between the damper and the specific blade mode, enabling effective energy dissipation even in the presence of mistuning and vibration localization that conventional dampers cannot address.
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 tuned vibration absorber achieves substantial amplitude reduction and increased damper effectiveness by redirecting energy through frictional dissipation, effectively reducing vibration levels across a broader frequency range and improving robustness against mistuning.
Implementation Method 1
the damper is designed to have a natural frequency matching that of the targeted IBR mode, enabling frictional dissipation and increased damper motion
Implementation Method 2
The tuned vibration absorber achieves substantial amplitude reduction and increased damper effectiveness by redirecting energy through frictional dissipation
Data Source
AI summary
A vibration absorber damper and method of dissipating vibration energy in a rotatable structure which is nominally cyclic symmetric. The nominally cyclic symmetric structure includes a hub portion having a rotational axis and a plurality of radial members radially extending from the hub portion. The hub portions having a groove extending circumferentially about the rotational axis. The vibrational absorber having a ring member having a plurality of repetitive cellular structures each defining a hollow interior section and a plurality of deformable members each extending from the ring member and disposed in a corresponding one of the repetitive cellular structures. Each of the deformable members is configured to interact with the cyclic symmetric structure to damp vibration thereof.