Experimental Investigation of a Simple Squeeze Film Damper

1974 ◽  
Vol 96 (2) ◽  
pp. 427-430 ◽  
Author(s):  
K. K. Thomsen ◽  
H. Andersen
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Point Of View ◽  
Squeeze Film ◽  
Theoretical Formula ◽  
Practical Application ◽  
Oil Viscosity ◽  
Squeeze Film Damper ◽  
Direct Measurements ◽  
Transmitted Force

This paper describes an experimental investigation of a squeeze film damper for the control of rotor amplitudes. From direct measurements of the transmitted force and the velocity of the damper sleeve, the damping coefficient of the squeeze film is obtained over a range of frequencies and for several values of film thickness and oil viscosity. The results are compared with the theoretical formula, based on assumptions of linearity, and from a practical application point of view the correlation is satisfactory.

Dynamic Analysis of a Coupled Dual-Rotor With Squeeze Film Damper Considering Sudden Unbalance

2021 ◽  
Author(s):  
Ying Cui ◽  
Yuxi Huang ◽  
Guogang Yang ◽  
Yongliang Wang ◽  
Han Zhang
Keyword(s):  
Steady State ◽  
Transient Response ◽  
Rotor System ◽  
Lubricating Oil ◽  
Squeeze Film ◽  
Radial Clearance ◽  
Oil Viscosity ◽  
Squeeze Film Damper ◽  
Damping Effect ◽  
Bistable State

Abstract A nonlinear multi-degree-of-freedom dynamic model of a coupled dual-rotor system with an intershaft bearing and uncentralized squeeze film damper is established by using finite element method. Based on the model, the critical speed characteristic diagram and vibration modes of the system were calculated. The steady-state unbalance response is obtained by using Newmark-β algorithm. The numerical results show the effect of SFD position in the dual-rotor system on response amplitude. It is found that with the decrease of radial clearance and the increase of length-diameter ratio and lubricating oil viscosity, the damping effect of SFD is enhanced and the bistable state phenomenon can be suppressed. The transient response of the system in case of sudden unbalance occurring at the fan was simulated by applying a step function. It is demonstrated that the SFD can effectively reduce the duration and maximum amplitude of the transient process, but at certain speeds, the SFD will increase the amplitude after the system returns to steady state, the damping effect on the transient response is also enhanced with the increase of length-diameter and the decrease of radial clearance, and with the increase of the sudden unbalance value, the response is more likely to stabilized at the high amplitude state of the bistable state.

The Control of Engine Vibration Using Squeeze Film Dampers

1983 ◽  
Vol 105 (3) ◽  
pp. 525-529 ◽  
Author(s):  
R. Holmes
Keyword(s):  
Experimental Work ◽  
Squeeze Film ◽  
Vibration Isolator ◽  
Squeeze Film Damper ◽  
Engine Vibration ◽  
Transmitted Force ◽  
Squeeze Film Dampers ◽  
Jump Phenomena ◽  
Theoretical Predictions ◽  
In Series

This paper describes the following roles of a squeeze-film damper when used in gas turbine applications as a means of reducing vibration and transmitted force due to unbalance: (a) as an element in parallel with a soft spring in a vibration isolator; and (b) as an element in series with the stiffness of the engine pedestal. The effects of cavitation on performance are elucidated, and the dangers of jump phenomena and subsynchronous response are discussed. Experimental work is described in which both roles of the squeeze-film damper are investigated and the results are compared with theoretical predictions.

Effect of Fluid Inertia on the Performance of Squeeze Film Damper Supported Rotors

1988 ◽  
Vol 110 (1) ◽  
pp. 51-57 ◽  
Author(s):  
L. A. San Andres ◽  
J. M. Vance
Keyword(s):  
Aircraft Engine ◽  
Reynolds Numbers ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Response Curves ◽  
Squeeze Film Damper ◽  
Steady State Operation ◽  
Transmitted Force ◽  
Jump Phenomena ◽  
Single Mass

The effect of fluid inertia on the synchronous steady-state operation of a centrally preloaded single mass flexible rotor supported in squeeze film bearing dampers is examined theoretically. For a model representative of some aircraft engine applications, frequency response curves are presented exhibiting the effect of fluid inertia on rotor excursion amplitudes and imbalance transmissibilities for both pressurized and unpressurized short open-ended squeeze film damper supports. It is shown that a significant reduction in amplitude response and transmitted force is possible for dampers operating at moderately large squeeze film Reynolds numbers. Furthermore, for unpressurized dampers the possibilities of bistable operation and jump phenomena are shown to be reduced and virtually disappear at sufficiently large operating Reynolds numbers.

scholarly journals The Control of Engine Vibration Using Squeeze-Film Dampers

1982 ◽  
Author(s):  
R. Holmes
Keyword(s):  
Experimental Work ◽  
Squeeze Film ◽  
Vibration Isolator ◽  
Squeeze Film Damper ◽  
Engine Vibration ◽  
Transmitted Force ◽  
Squeeze Film Dampers ◽  
Jump Phenomena ◽  
Theoretical Predictions ◽  
In Series

This paper describes the following roles of a squeeze-film damper when used in gas turbine applications as a means of reducing vibration and transmitted force due to unbalance. (a) as an element in parallel with a soft spring in a vibration isolator and (b) as an element in series with the stiffness of the engine pedestal. The effects of cavitation on performance are elucidated and the dangers of jump phenomena and subsynchronous response are discussed. Experimental work is described in which both roles of the squeeze-film damper are investigated and the results are compared with theoretical predictions.

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 Experimental Investigation of the Torque Efficiency in Small Supr Gears

2015 ◽  
Vol 642 ◽  
pp. 292-297
Author(s):  
Jian Shing Lee ◽  
Jeng Haur Horng ◽  
Ming Yuan Chiu
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Power Loss ◽  
Applied Load ◽  
Opposite Effect ◽  
High Viscosity ◽  
Oil Viscosity ◽  
Limited Effect ◽  
Gear Transmission System ◽  
High Viscosity Oil

In present study, a gear transmission system was used to evaluate the effects of oil viscosity, speed, oil temperature as well as the applied load on torque efficiency. The experimental results reveal that the efficiency is increased with the increasing oil temperature and/or applied load whether the multigrade or singlegrade oil was employed. Under a constant torgue, the power loss is increased with the increasing pitch line velocity. The above characteristic resulting from the use of high-viscosity oil yields the substantial variations. However, as the oil film thickness is quite small, the viscosity speed, oil temperature and applied load produces the limited effect on torque efficiency, It indicate that EP additives create an opposite effect on torque efficiency at poor lubrication.

An Experimental Investigation Into the Effect of Lubricant on the Local Film Thickness of Artificial Roughness Features

2008 ◽  
Author(s):  
M. D. Furtuna ◽  
R. P. Glovnea
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Experimental Work ◽  
Good Deal ◽  
Viscosity Coefficient ◽  
Point Of View ◽  
Experimental Point ◽  
Artificial Roughness ◽  
Random Roughness ◽  
Interferometry Method

The lubrication of rough surfaces has been a focus of researchers in the field for many years now. A good deal of work has been carried out either on the experimental or on the theoretical sides of the research. From the experimental point of view it is obviously more convenient to study the lubrication of artificial roughness features such as ridges, bumps or dents rather than real, random roughness. The advantage of model roughness features is that they are well individualized, located, and characterized, thus a comparison of the surfaces geometry inside and outside an elastohydrodynamic contact can be made. The studies carried out so far have focused on the effect of the geometry of the features and that of the entrainment speed. No detailed experimental work on the effect of the lubricant properties on the behavior of the EHD films has been performed, to the authors’ knowledge. The present study uses the optical interferometry method to measure the EHD film thickness between a flat disc and a ball on which artificial ridges have been sputtered. Two lubricants, with different viscosity and pressure/viscosity coefficient are used in a range of pressures and entrainment speeds.

Vibration Reduction Investigation of a Squeeze Film Damper With Valvular Metal Rubber

2006 ◽  
Author(s):  
Ma Yanhong ◽  
Hong Jie ◽  
Deng Yin
Keyword(s):  
Film Thickness ◽  
Working Condition ◽  
Vibration Reduction ◽  
Squeeze Film ◽  
Experimental Investigations ◽  
Squeeze Film Damper ◽  
Metal Rubber ◽  
Unbalance Force ◽  
Optimal Effect ◽  
Better Than

A new-style squeeze film damper with valvular metal rubber squeeze film ring (SFD/VMR) was designed to improve characteristics of the squeeze film force of the SFD. The immobile squeeze film ring of the SFD was replaced by the elastic squeeze film ring with the valvular metal rubber subassembly (VMR). When the unbalance force was smaller, the displacement of the journal changed little, and then the squeeze film force was smaller too, so as to the squeeze film ring of the SFD/VMR was nearly immobile. The working condition was similar with the SFD. When the unbalance force was larger, the displacement of the journal changed bigger, and then the squeeze film force rapidly increased, so as to the VMR deformed, which made the film thickness changed correspondingly, until it reached a balanceable state of the squeeze film force and elastic force of the VMR. Theoretical and experimental investigations showed that the SFD/VMR had optimal effect on reducing vibration, comparing with the SFD, because it could passively adjust the squeeze film clearance by taking advantage of the elastic deformation of the VMR. The SFD/VMR could control the squeeze film clearance in a suitable range, which made the characteristics of the squeeze film force of the SFD/VMR better than the SFD. The SFD/VMR could suppress the occurrence of the nonlinear vibration phenomenon markedly, such as bistable jump up.

Dynamic behavior analysis of a rigid rotor supported by hydrostatic squeeze film dampers compensated with new electrorheological valve restrictors

2019 ◽  
Vol 72 (5) ◽  
pp. 611-619 ◽  
Author(s):  
Mohamed Benadda ◽  
Ahmed Bouzidane ◽  
Marc Thomas ◽  
Raynald Guilbault
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Nonlinear Models ◽  
Squeeze Film ◽  
Rigid Rotor ◽  
Eccentricity Ratio ◽  
Content Type ◽  
Squeeze Film Damper ◽  
Transmitted Force ◽  
Squeeze Film Dampers

Purpose This paper aims to propose a new hydrostatic squeeze film damper compensated with electrorheological valve restrictors to control the nonlinear dynamic behavior of a rigid rotor caused by high unbalance eccentricity ratio. To investigate the effect of electrorheological valve restrictors on the dynamic behavior of a rigid rotor, a nonlinear model is developed and presented. Design/methodology/approach The nonlinear results are compared with those obtained from a linear approach. The results show good agreement between the linear and nonlinear methods when the unbalanced force is small. The effects of unbalance eccentricity ratio and electric field on the vibration response and the bearing transmitted force are investigated using the nonlinear models. Findings The results of simulation performed that the harmonics generated by high unbalance eccentricities can be reduced by using hydrostatic squeeze film damper compensated with electrorheological valve restrictors. Originality/value The numerical results demonstrate that this type of smart hydrostatic squeeze film damper provides to hydrostatic designers a new bearing configuration suitable to control rotor vibrations and bearing transmitted forces, especially for high speed.

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