Unbalance Response Control of Rotor by Magneto-Rheological Fluid Based Squeeze Film Damper

2005 ◽  
Author(s):  
Keun-Joo Kim ◽  
Chong-Won Lee
Keyword(s):  
Dynamic Stiffness ◽  
Squeeze Film ◽  
Effective Control ◽  
Control Algorithms ◽  
Value Analysis ◽  
Squeeze Film Damper ◽  
Unbalance Response ◽  
Flexible Rotors ◽  
Magneto Rheological ◽  
And Control

In this work, a magneto-rheological fluid based semi-active squeeze film damper (MR-SFD) is successfully applied to attenuate the excessive vibrations, especially unbalance responses, of a flexible rotor-bearing system. Using the linearized dynamic stiffness model of the MR-SFD, the optimal design and control algorithms that can effectively control excessive unbalance responses of flexible rotors are also proposed; the optimal damper location considering several flexible modes is systematically explored by means of the Structural Dynamics Modification technique. A simple, yet effective, control algorithm is also established in which the optimal input current levels are scheduled by using the singular value analysis. It is shown that the simulation and experimental results with a test rotor are in good agreement and that the proposed design and control algorithms of the MR-SFD are very effective in attenuation of unbalance response of the test rotor up to the second critical speed.

Optimal Positioning and Control of a MR-Squeeze Film Damper for Reducing Unbalanced Vibrations in a Rotor System With Multiple Masses

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Keun-Joo Kim ◽  
Chong-Won Lee ◽  
Jeong-Hoi Koo
Keyword(s):  
Control Algorithm ◽  
Critical Speed ◽  
Numerical Study ◽  
Rotor System ◽  
Squeeze Film ◽  
Optimal Position ◽  
Value Analysis ◽  
Squeeze Film Damper ◽  
Control Scheme ◽  
And Control

This paper presents a new semi-active control scheme that can reduce the unbalance responses in a flexible rotor system with multiple masses (i.e., disks) using a magnetorheological fluid based squeeze film damper (MR-SFD). The proposed control scheme is designed to effectively attenuate multiple vibration modes of the rotor system. The control algorithm begins with the determination of the optimal location of the MR squeeze film damper to maximize its control performance over several flexural critical speeds of interest. After identifying the optimal position of the damper based on the structure dynamics modification method, the singular value analysis was performed, with varying rotor speed, to determine the scheduled input current to the MR squeeze film damper at each rotational speed. Using a rotor-bearing model coupled with three disks and a MR-SFD, a series of numerical simulations was performed to evaluate the effectiveness of the control algorithm. In addition to the numerical study, a test rotor system (equivalent to the numerical model) and a prototype MR squeeze film damper were constructed and tested to experimentally evaluate the performance of the prototype with the control and validate the simulation results. The numerical and test results indicate that optimal positioning of the damper alone (without implementing the control) significantly reduced the unbalance responses of the disks near the first critical speed. Activating the controller, the damper further attenuated the unbalanced vibrations of the rotor system at the second critical speed. The results show that, at this critical speed, the peak vibration magnitudes of the disks were attenuated by nearly 70%.

Active Control Algorithms for the Control of Rotor Vibrations Using HSFDs

2000 ◽  
Author(s):  
A. El-Shafei
Keyword(s):  
Active Control ◽  
Gain Scheduling ◽  
Rotating Machinery ◽  
Squeeze Film ◽  
Control Algorithms ◽  
Critical Stage ◽  
Squeeze Film Damper ◽  
Active Vibration

The Hybrid Squeeze Film Damper (HSFD) has proven itself to be an effective controlling device of vibration in rotating machinery. The critical stage in the development of the HSFD as an active vibration suppressant, is the development of the control algorithms for active control of rotor vibrations. This paper summarizes, evaluates and compares the control algorithms for HSFD supported rotors. Quantitative as well as qualitative measures of the effectiveness of the control algorithms are presented. The study includes the PID-type controllers, LQR, gain scheduling, adaptive and bang-bang controllers. The adaptive, gain scheduling and nonlinear proportional controllers, have proved to be quite effective in the active control of HSFD supported rotors, with impressive results.

Design of a novel magneto-rheological squeeze-film damper

2006 ◽  
Vol 15 (1) ◽  
pp. 164-170 ◽  
Author(s):  
C Carmignani ◽  
P Forte ◽  
E Rustighi
Keyword(s):  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Magneto Rheological

Electro-Rheological Multi-layer Squeeze Film Damper and Its Application to Vibration Control of Rotor System

1999 ◽  
Vol 122 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Yao Guozhi ◽  
Yap Fook Fah ◽  
Chen Guang ◽  
Meng Guang ◽  
Fang Tong ◽  
...  
Keyword(s):  
Vibration Control ◽  
Large Amplitude ◽  
Critical Speed ◽  
Reynolds Equation ◽  
Control Method ◽  
Rotor System ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Unbalance Response ◽  
Er Damper

In this paper, a new electro-rheological multi-layer squeeze film damper (ERMSFD in short) is designed first and the constitutional Reynolds equation is established. Then the behavior of the rotor system is analyzed, the vibration around the first critical speed is suppressed and an on/off control is proposed to control the large amplitude around the first critical speed. A control method is used to suppress the sudden unbalance response. Finally, experiments are carried out to investigate the behavior of the rotor system to prove the effectiveness of the ER damper to suppress the vibration around the critical speed and the sudden unbalance response. [S0739-3717(00)00301-9]

Sliding Mode Control of Flexible Rotor Using Magneto Rheological Squeeze Film Damper

2012 ◽  
Author(s):  
Masoud Hemmatian ◽  
Abdolreza Ohadi
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Open Loop ◽  
Squeeze Film ◽  
Flexible Rotor ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Squeeze Film Damper ◽  
Model Base ◽  
Magneto Rheological

This study aims to control the vibration of a flexible rotor system using magneto rheological squeeze film damper (MR-SFD). To evaluate the performance of damper, Bingham plastic model is used for MR fluid and the hydrodynamic equation of MR-SFD is presented. The remarkable point about this equation is the necessity of using numerical methods to solve it. These methods are too costly and impossible especially in the simulation of complex rotors and implementation of model base controllers. To fix this issue, an estimated equation is used in this paper for pressure distribution throughout the damper. By integration of this expression, hydrodynamic forces of MR-SFD are calculated as an algebraic equation. Furthermore, sliding mode controller is chosen as robust control method by considering the structural and parametric uncertainties of the system. Study time and frequency responses of flexible rotor in presence of these controllers show a good performance in reducing vibration of shafts midpoint. The results for the open loop system also indicate that changing the stiffness coefficient of elastic foundation and the temperature of MR fluid (as two uncertainties of system) strongly affects the outputs while using sliding mode controllers well increases the robustness of the system.

Use of the Harmonic Balance Method for Flexible Aircraft Engine Rotors With Nonlinear Squeeze Film Dampers

2014 ◽  
Author(s):  
Feng He ◽  
Paul Allaire ◽  
Timothy Dimond
Keyword(s):  
Harmonic Balance ◽  
Harmonic Balance Method ◽  
Aircraft Engine ◽  
Balance Method ◽  
Squeeze Film ◽  
Spring Stiffness ◽  
Squeeze Film Damper ◽  
Flexible Rotors ◽  
Squeeze Film Dampers ◽  
Nonlinear Transient

Squeeze film dampers in flexible rotors such as those in compressors, steam turbines, aircraft engines and other rotating machines are often modeled as linear devices. This linearization is valid only for a specified orbit where appropriate equivalent stiffness and damping coefficients can be found. However, squeeze film dampers are inherently nonlinear devices which complicates the analysis. This paper develops the harmonic balance method with a direct force model of the SFDs. This model is used for flexible rotors with squeeze film dampers where the rotor is treated as linear and the squeeze film damper is treated as nonlinear. The predictor-corrector method is employed to obtain the system forced response in the frequency domain after separating the nonlinear components from the linear components of the equations of motion. This approach is much more efficient than conventional full nonlinear transient analysis. The application considered in this paper is the low pressure (LP) compressor of an aircraft engine. The LP compressor rotor has two roller bearings with squeeze film dampers and one ball bearing without a squeeze film damper. Orbits at the fan end dampers and the turbine end dampers for both the harmonic balance and nonlinear transient modeling are compared for accuracy and calculation time. The HB method is shown to be 5 to 12 times faster computationally for similar results. Fast Fourier transform results were obtained for various shaft operating speeds. Results were also obtained for the unbalance response at different locations with gravity loading. Finally, unbalance response of the rotor with varying centering spring stiffness values were obtained. The results show that the centering spring stiffness for the turbine end damper is less sensitive than the fan end damper.

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