scholarly journals An Investigation Into the Effect of Side-Plate Clearance in an Uncentralized Squeeze-Film Damper

1983 ◽  
Author(s):  
R. A. Cookson ◽  
L. J. Dainton
Keyword(s):  
Experimental Investigation ◽  
Rolling Contact ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Flexible Rotor ◽  
Jump Phenomenon ◽  
Side Plate ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers ◽  
Experimental Rig

An experimental investigation has been carried out into the influence of side-plate flow restrictors on the performance of a squeeze-film damper bearing. The experimental rig used was a flexible rotor with a disc positioned mid-way between two squeeze-film damper bearings. One of the squeeze-film dampers was fitted with side-plates which could be adjusted and accurately located with respect to the squeeze-film damper journal. It has been found that the influence of the side-plate clearance on the ability of the squeeze-film damper to reduce the amplitude of the central disc can be considerable if the side-plate clearance is less than the radial clearance. As the side-plate clearance reduces towards zero, the effectiveness of the squeeze-film damper diminishes until the amplitudes obtained are the same as those measured when the rolling-contact bearing is rigidly supported. An interesting type of precessing elliptical orbit was discovered for conditions where the ‘jump’ phenomenon was operating.

An Investigation Into the Effect of Side-Plate Clearance in an Uncentralized Squeeze Film Damper

1983 ◽  
Vol 105 (4) ◽  
pp. 935-940
Author(s):  
R. A. Cookson ◽  
L. J. Dainton
Keyword(s):  
Rolling Contact ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Flexible Rotor ◽  
Jump Phenomenon ◽  
Side Plate ◽  
Squeeze Film Damper ◽  
Central Disk ◽  
Squeeze Film Dampers ◽  
Experimental Rig

An experimental investigation has been carried out into the influence of side-plate flow restrictors on the performance of a squeeze film damper bearing. The experimental rig used was a flexible rotor with a disk positioned midway between two squeeze film damper bearings. One of the squeeze film dampers was fitted with side plates that could be adjusted and accurately located with respect to the squeeze film damper journal. It has been found that the influence of the side-plate clearance on the ability of the squeeze film damper to reduce the amplitude of the central disk can be considerable if the side-plate clearance is less than the radial clearance. As the side-plate clearance reduces towards zero, the effectiveness of the squeeze film damper diminishes until the amplitudes obtained are the same as those measured when the rolling-contact bearing is rigidly supported. An interesting type of precessing elliptical orbit was discovered for conditions where the “jump” phenomenon was operating.

The Effect of Bistable Jump on the Reliability of Squeeze Film Damper

1991 ◽  
Author(s):  
Zhu Changsheng
Keyword(s):  
High Speed ◽  
Operating Time ◽  
Squeeze Film ◽  
Jump Phenomenon ◽  
Rotor Vibration ◽  
Squeeze Film Damper ◽  
Operation Speed ◽  
Squeeze Film Dampers ◽  
Speed Range ◽  
Pass Through

Abstract Based on lots of data from an experiment of a high-speed rotor supported on squeeze film dampers, this paper analyses that how the bistable jump affects the reliability of squeeze film dampers, if the rotor system has to frequently pass through the bistable oparation speed range. It is shown that the change of the rotor vibration amplitudes caused by times of passed through bistable operation speed range is more significant than that caused by steady operating time. The users must pay much attention to the bistable jump phenomenon in the successful application of squeeze film dampers.

scholarly journals The Effect of Squeeze Film Damper Parameters on the Unbalance Response and Stability of a Flexible Rotor

1996 ◽  
Author(s):  
F. Chu ◽  
R. Holmes
Keyword(s):  
Research Work ◽  
Stability Control ◽  
Squeeze Film ◽  
Flexible Rotor ◽  
Squeeze Film Damper ◽  
Significant Movement ◽  
Squeeze Film Dampers ◽  
Bearing Assembly ◽  
Static Eccentricity ◽  
Points Of View

There has been much research work carried out on various aspects of individual squeeze-film dampers (SFDs) but very little on the interplay between a damper and the rotating assembly of which it forms a part. In this paper, a flexible rotor-bearing assembly in a configuration, typical of a small centrifugal pump and incorporating an SFD is investigated theoretically and experimentally from the points of view of forced vibration control and stability control. It is found that change in rotor unbalance, SFD static eccentricity ratio and SFD supply pressure can cause significant movement of system resonances and vibration resulting from excessive damping. The provision of an SFD also delays the onset of instability and because of its nonlinearity, the SFD contributes more damping than can a linear damper when the vibration amplitude becomes large as instability develops. It is shown that this instability is curbed at some limit cycle, whose frequency is a system natural frequency.

An Appraisal of a Proposed Active Squeeze Film Damper

1991 ◽  
Vol 113 (4) ◽  
pp. 750-754 ◽  
Author(s):  
C. Mu ◽  
J. Darling ◽  
C. R. Burrows
Keyword(s):  
Theoretical Model ◽  
Vibration Control ◽  
Numerical Experiments ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Flexible Rotor ◽  
Oil Film ◽  
Squeeze Film Damper

A theoretical model for an active squeeze film damper (SFD) is introduced. The design makes it possible to change the radial clearance and land length of the SFD by adjusting the position of the damper ring. Expressions for the oil film forces are obtained. The vibration control of a flexible rotor is taken as an example of the application of the new design. The possibility of controlling rotor vibrations is demonstrated by means of numerical experiments.

The Effect of Squeeze Film Damper Parameters on the Unbalance Response and Stability of a Flexible Rotor

1998 ◽  
Vol 120 (1) ◽  
pp. 140-148 ◽  
Author(s):  
F. Chu ◽  
R. Holmes
Keyword(s):  
Research Work ◽  
Stability Control ◽  
Squeeze Film ◽  
Flexible Rotor ◽  
Squeeze Film Damper ◽  
Significant Movement ◽  
Squeeze Film Dampers ◽  
Bearing Assembly ◽  
Static Eccentricity ◽  
Points Of View

There has been much research work carried out on various aspects of individual squeeze-film dampers (SFDs) but very little on the interplay between a damper and the rotating assembly of which it forms a part. In this paper, a flexible rotor-bearing assembly in a configuration, typical of a small centrifugal pump and incorporating an SFD, is investigated theoretically and experimentally from the points of view of forced vibration control and stability control. It is found that change in rotor unbalance, SFD static eccentricity ratio, and SFD supply pressure can cause significant movement of system resonances and vibration resulting from excessive damping. The provision of an SFD also delays the onset of instability and because of its nonlinearity, the SFD contributes more damping than can a linear damper when the vibration amplitude becomes large as instability develops. It is shown that this instability is curbed at some limit cycle, whose frequency is a system natural frequency.

The Effect of Journal Misalignment on the Oil-Film Forces Generated in a Squeeze Film Damper

1983 ◽  
Vol 105 (3) ◽  
pp. 560-564 ◽  
Author(s):  
R. A. Cookson ◽  
X. H. Feng ◽  
S. S. Kossa
Keyword(s):  
Computational Procedure ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Oil Film ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers ◽  
Unbalance Force ◽  
Orbit Size ◽  
Journal Misalignment ◽  
Typical Calculation

Squeeze film damper performance is usually assessed on the assumption that the axis of the journal is parallel to that of the bearing housing. For many practical cases, for example that of the overhung fan shaft in an aero gas turbine, these two elements are unlikely to be parallel, even when self-aligning bearings are used. In this theoretical study an attempt has been made to evaluate the effect of misalignment on the magnitude of the oil-film forces produced in a squeeze film damper bearing, and to this end a computational procedure has been established. From the results reported in this paper, it has been clearly shown that the effect of misalignment in a two-land, squeeze film damper can lead to a significant increase in the transmission of unbalance force through the oil film, As an example, data from a previously reported investigation into the performance of a simple two-bearing model with a single centrally supported disk have been used in a typical calculation. The results from this computation indicated that the oil-film forces generated, could have been several times greater than those calculated on the assumption that the journal and bearing housing were parallel. Unfortunately, there do not appear to be any clear guidelines to lay down to the designers of squeeze film dampers at this moment, in relation to journal misalignment. In general, the effect of misalignment is strongest when the ratio of land-length to radial clearance is greatest, when large unbalance is being accommodated, and when the orbit size is large. In our own analytical studies, the effect of misalignment is allowed for whenever the angle of misalignment is greater than 0.0005 radians.

The influence of fluid inertia forces on the sudden unbalance responses of squeeze-film damper supported rotors

1998 ◽  
Vol 212 (5) ◽  
pp. 353-357 ◽  
Author(s):  
G Meng ◽  
Y-C Guo ◽  
E. J. Hahn
Keyword(s):  
Transient Process ◽  
Vibration Amplitude ◽  
Constant Speed ◽  
Squeeze Film ◽  
Flexible Rotor ◽  
Fluid Inertia ◽  
Transient Vibration ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers ◽  
Inertia Forces

The influence of fluid inertia on the sudden unbalance response of a flexible rotor supported on centralized and uncentralized squeeze-film dampers is investigated. Whether the rotor is at constant speed or accelerating, it was generally found that fluid inertia shortens the transient process and decreases the transient vibration amplitude. Qualitatively, the effect of fluid inertia is similar to increased damping.

Experimental Study on the Vibration Control Capability of a Hybrid Squeeze Film Damper

2001 ◽  
Author(s):  
Changsheng Zhu
Keyword(s):  
Dynamic Characteristics ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Flexible Rotor ◽  
Nonlinear Characteristics ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Hybrid Combination ◽  
Highly Nonlinear ◽  
Control Capability

In order to improve the highly nonlinear characteristics of the conventional hydrodynamic squeeze film damper (SFD) in high journal eccentricity ratios and make its dynamic characteristics controllable, a hybrid (combination hydrostatic and hydrodynamic) squeeze film damper (HSFD) is presented. The effectiveness of the hybrid squeeze film damper in attenuating vibration of rotor systems and in improving the high non-linearity of oil film forces of the conventional hydrodynamic SFD is experimentally studied in this paper with a rigid rotor and a flexible rotor. The steady state unbalance responses of rotor-HSFD systems are compared with those of rotor-SFD systems in different radial clearance ratios. It is shown that the HSFD has very good linear dynamic characteristics and can effectively attenuate vibration of rotor systems, especially in larger rotor unbalances and large radial clearance ratios.

Experimental Investigation of the Design Parameters and of the Working Conditions on the Global Characteristics of a Squeeze Film Damper

2005 ◽  
Author(s):  
Cyril Defaye ◽  
Philippe Carpentier ◽  
Charles Debailleux ◽  
Mihai¨ Arghir ◽  
Olivier Bonneau ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Working Conditions ◽  
Experimental Result ◽  
Squeeze Film ◽  
Experimental Program ◽  
Design Parameters ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers

Squeeze film dampers (SFD) is a topical subject since almost four decades [1, 2] but the need of experimental result is still stringent. The present work introduces the results of an experimental program aimed to investigate the influence of the design parameters and of the working conditions on the global characteristics of sealed SFD.

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