Tuned Ring Absorber Dampers for Blade-Dominated 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 rely on relative motion between the damper and the rotor, which is limited by the geometry and lack of frictional joints, leading to inefficient energy dissipation across multiple operation regimes.
Innovation Solution
A tuned vibration absorber damper concept that incorporates nonlinear dissipation through geometric and material variations, ensuring large damper motion and effective frictional energy transfer, allowing the damper to target blade-dominated modes and maintain effectiveness across various frequency ranges by matching its natural frequency with the rotor's modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ring dampers are used, then damping is provided through relative motion at the interface, but the effectiveness is limited due to small motion in areas away from blade root and inability to target blade-dominated modes
Solution Approach 1:
Instead of relying on relative motion between damper and rotor (conventional approach), the invention inverts the approach by creating a tuned vibration absorber where the damper is designed to have natural frequency matching the rotor's blade-dominated modes. The absorber is intentionally tuned to resonate at the target frequency, causing large amplitude motion in the absorber itself rather than relying on interface motion.
Solution Approach 2:
The invention changes key parameters of the damper including its natural frequency (tuned to match blade-dominated modes), mass distribution, and stiffness characteristics. By adjusting these parameters, the absorber is optimized to resonate at specific frequencies and transfer energy effectively from the rotor to the absorber, achieving damping where conventional dampers fail.
2Loss of energy
If friction-based damping mechanisms are used, then energy dissipation occurs through friction, but the damping effectiveness is insufficient for blade-dominated modes due to lack of frictional joints in IBR geometry
Solution Approach 1:
The tuned vibration absorber acts as an intermediary system that mediates energy transfer between the rotor and the dissipation mechanism. The absorber receives vibrational energy from the rotor through tuned resonance, amplifies it through its own motion, and then dissipates it through friction elements (such as friction pads or contact surfaces) that are specifically designed to engage during absorber motion. This intermediary approach overcomes the lack of frictional joints in the original IBR geometry.
3Reliability
If tuned vibration absorbers are used, then energy is transferred from critical components to the absorber, but the absorber must be precisely tuned to narrow frequency ranges which reduces robustness to mistuning and operational variations
Solution Approach 1:
The invention introduces dynamic characteristics to the absorber system, including nonlinear friction elements that provide amplitude-dependent damping, and potentially adjustable parameters that allow the absorber to adapt to different operating conditions. The friction-based dissipation mechanism provides nonlinear damping that can maintain effectiveness across a broader frequency range compared to purely linear tuned absorbers.
Solution Approach 2:
The absorber employs composite damping mechanisms combining tuned mass-spring elements with friction-based nonlinear damping elements. This composite approach merges the frequency-selective energy transfer of tuned absorbers with the broadband dissipation capability of friction dampers, creating a hybrid system that maintains effectiveness across wider frequency ranges and is more robust to mistuning.
4Strength
If the damper is positioned away from blade root to avoid stress concentrations, then stress is reduced, but the motion available for damping is minimal
Solution Approach 1:
The invention segments the damping function into two separate components: (1) the absorber mass-spring system that is positioned away from the blade root to avoid stress concentrations and capture vibrational energy, and (2) the friction dissipation elements that are strategically placed to engage during absorber motion. This segmentation allows each component to be optimized for its specific function without compromise.
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 damper achieves significant amplitude reduction and frequency splitting, enhancing damping effectiveness for blade-dominated modes and demonstrating robustness to mistuning and operational variations, thereby reducing the risk of blade failure from high-cycle fatigue.
Implementation Method 1
The tuned vibration absorber damper concept incorporates nonlinear dissipation through geometric and material variations, ensuring large damper motion and effective frictional energy transfer
Implementation Method 2
The key idea is to exploit resonance of the damper component to induce dissipation through friction, increasing effectiveness
Data Source
Figure 1A~2
Figure 3~4
Figure 5~6
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.