Piezoelectric Actuator for Dynamic Oil Film Clearance Control
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Solution Overview
Problem
Traditional squeeze film dampers in turboshaft engines face challenges with inflexibility, slow response, and low control accuracy in adapting to complex working conditions and rotor imbalance, leading to uncontrollable vibration.
Innovation Solution
A method and system that establish a mapping matrix between rotor unbalance, oil film clearance, and vibration response, using real-time data to adjust oil film clearance through a PID controller and neural network optimized control signal, driven by piezoelectric ceramic actuators to quickly and precisely control vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a traditional squeeze film damper is used to attenuate rotor vibration, then the structure is simple and space occupation is small, but the oil film clearance is uncontrollable and cannot adapt to complex working conditions
Solution Approach 1:
The patent transforms the static oil film clearance of traditional dampers into a dynamically adjustable parameter. Piezoelectric ceramic actuators are integrated into the damper structure, enabling real-time modification of the oil film clearance based on operating conditions. This dynamic adjustment capability allows the system to adapt to varying rotor speeds, eccentricities, and vibration levels, resolving the contradiction between structural simplicity and adaptability.
Solution Approach 2:
The patent changes the physical parameter of oil film clearance from a fixed value to a controllable variable. By applying voltage to the piezoelectric actuators, the clearance can be precisely adjusted according to the mapping matrix that correlates clearance with vibration response. This parameter change enables the damper to optimize its damping performance across different working conditions while maintaining a relatively simple overall structure.
2Reliability
If a hydraulic adjusting screw is used to adjust oil film clearance, then vibration attenuation is achieved, but the response is slow and flexibility is reduced
Solution Approach 1:
The patent replaces the mechanical hydraulic adjusting screw system with an electro-ceramic actuation system. Piezoelectric ceramics convert electrical signals directly into mechanical displacement, eliminating the need for hydraulic fluid, valves, and mechanical linkages. This substitution enables rapid response to vibration changes while maintaining effective clearance adjustment, resolving the contradiction between reliable vibration attenuation and fast response speed.
Solution Approach 2:
The patent uses piezoelectric actuators that can precisely replicate the desired clearance adjustments calculated by the control system. The actuators copy the motion profile required to optimize damping, responding instantly to control signals and accurately achieving the target clearance positions, thereby providing both reliability and speed.
3Adaptability or versatility
If a tapered damping chamber is used to adjust oil film radius clearance, then some adaptation is achieved, but the adjustment accuracy is poor and significant damping effect cannot be yielded
Solution Approach 1:
The patent implements a closed-loop feedback control system that continuously monitors vibration response and adjusts the oil film clearance accordingly. Sensors measure the actual vibration levels, which are compared against target values in the mapping matrix. The control system then generates correction signals to the piezoelectric actuators, ensuring high precision in achieving the optimal clearance. This feedback mechanism resolves the contradiction between adaptability and adjustment accuracy.
Solution Approach 2:
The patent employs dynamic adjustment of oil film clearance based on real-time operating conditions. The piezoelectric actuators can make fine, incremental adjustments to the clearance, unlike static or coarsely-adjusted traditional dampers. This dynamic precision control enables the system to achieve both adaptability to varying conditions and high accuracy in clearance positioning, yielding significant damping effects.
4Reliability
If the oil film clearance of squeeze film damper is adjusted with hydraulic adjusting screw, then vibration attenuation is realized, but it is inflexible and difficult to respond quickly to rotor vibration problems
Solution Approach 1:
The patent replaces the manual or mechanically-controlled hydraulic adjusting screw with an electronically-controlled piezoelectric actuation system. The electronic control allows for programmable adjustment schedules, automatic response to vibration sensors, and integration with the engine's control system. This substitution provides both reliable vibration damping and operational flexibility, as the system can be easily reconfigured for different operating scenarios without mechanical reconfiguration.
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
Enables quick and real-time adaptation to rotor imbalance, improving damping effect and control accuracy, effectively managing complex working conditions and reducing the risk of vibration-related accidents.
Implementation Method 1
obtaining, based on the preferred oil film clearance and the real-time oil film clearance, a clearance adjustment amount; and generating a control signal based on the clearance adjustment amount, and performing adjustment based on the control signal
Data Source
AI summary
A method and system for controlling a vibration of a rotor in a turboshaft engine are provided. The method includes: establishing, based on a kinetic model for a rotor-casing system, a mapping matrix indicating a correspondence among an unbalance, an oil film clearance, and a vibration response; performing determination on a real-time vibration response, and skipping adjustment if the real-time vibration response is smaller than a response threshold; otherwise, approximately matching a real-time oil film clearance and the real-time vibration response with the mapping matrix to obtain a real-time unbalance; obtaining, based on the real-time unbalance and the mapping matrix, a preferred vibration response, and further obtaining a preferred oil film clearance; based on the preferred oil film clearance and the real-time oil film clearance, obtaining a clearance adjustment amount; generating a control signal based on the clearance adjustment amount, and performing adjustment based on the control signal.