scholarly journals Experimental Investigation of the Dynamic Response of Squeeze Film Dampers Made of Steel and Glass/Epoxy

2008 ◽  
Vol 15 (6) ◽  
pp. 631-637 ◽  
Author(s):  
Waleed F. Faris ◽  
Asad A. Khalid ◽  
A. Albagul ◽  
Godem A. Ismail
Keyword(s):  
Vibration Amplitude ◽  
Epoxy Composite ◽  
Diameter Ratio ◽  
Squeeze Film ◽  
Test Rig ◽  
Pressure System ◽  
Squeeze Film Damper ◽  
Weight Saving ◽  
Squeeze Film Dampers ◽  
Steel Damper

This work is devoted to the fabrication and investigation of the Squeeze Film Dampers (SFDs) which are widely used in many applications. This include the fabrication of a test rig and several dampers with different sizes and two different materials which composite and non-composite. Composite dampers (Glass/epoxy), each consists of 30 layers, were fabricated by hand lay-up method. Outer and inner diameters of all the fabricated dampers were maintained as 60 and 40 mm respectively. Non-composite dampers (Steel) were fabricated and tested using turning machine. Three dampers of different lengths were examined for both materials. A rotor-bearing system for the analysis has been designed and fabricated. The test rig consists of mild steel shaft, two supports, oil pressure system, and two self-alignment ball bearings were fixed on each end support. Two squeeze film dampers were used for the two support ends. Vibration amplitude has been examined for all the fabricated dampers at different shaft rotational speeds. The first resonance speed was examined for all the dampers tested. Results show that the vibration amplitude of the steel damper was lower than Glass/epoxy dampers with the same L/D ratio. On the other hand, a considerable weight saving has been achieved by using Glass/epoxy composite dampers. It has been found that the performance of squeeze film damper improved with increasing length/diameter ratio (L/D) within the range tested.

scholarly journals An Experimental Study on Steel and Teflon Squeeze Film Dampers

2006 ◽  
Vol 13 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Asad A. Khalid ◽  
A. Albagul ◽  
W. Faris ◽  
Godem A. Ismail
Keyword(s):  
Vibration Analysis ◽  
Vibration Amplitude ◽  
Pressure Gauge ◽  
Squeeze Film ◽  
Eccentricity Ratio ◽  
Test Rig ◽  
At Resonance ◽  
Squeeze Film Dampers ◽  
Rotor Support ◽  
Steel Damper

In this paper, the vibration analysis on Teflon and steel squeeze film dampers has been carried out. At different frequency ranges, vibration amplitude and the resonance frequency are measured. The eccentricity ratio at resonance speed has been determined. Results show that the vibration amplitude of the steel damper is 10% less at resonance compared with the Teflon damper. On the other hand, saving weight of 36% has been achieved by using the Teflon damper.A rotor bearing system for vibration analysis has been designed and fabricated. The test rig consists of mild steel shaft with two supports, oil pressure gauge system and two self-alignment ball bearings fixed on each end support. Two squeeze film dampers are used at each of the rotor support ends. Teflon and steel squeeze film dampers (SFD) were fabricated and tested using turning machine.

Effects of Adding a Central Groove to the Squeeze Film Damper Lands

2013 ◽  
Author(s):  
Praneetha Boppa ◽  
Aarthi Sekaran ◽  
Gerald Morrison
Keyword(s):  
Vibration Amplitude ◽  
High Speed ◽  
Dynamic Pressure ◽  
Aerospace Industry ◽  
Squeeze Film ◽  
Structural Components ◽  
Squeeze Film Damper ◽  
Pressure Profiles ◽  
Squeeze Film Dampers ◽  
Bearing System

Squeeze film dampers (SFDs) are used in the high speed turbo machinery industry and aerospace industry as a means to reduce vibration amplitude, to provide damping, to improve dynamic stability of the rotor bearing system and to isolate structural components. Past studies have not included effects of variation of the stator geometries in a squeeze film damper. A central groove added to the squeeze film land is hypothesized to provide a uniform flow source which theory predicts will result in forces less than one fourth of that seen in SFDs without a central groove. In the present study, 3D numerical simulations of SFDs with different size central grooves on the squeeze film land are performed to predict the variation of the dynamic pressure profiles. The numerical model and method have been validated via comparison to experimental data for a SFD without a central groove. When a central groove is added to the squeeze film land, the pressures generated are reduced to half of that generated when run without a central groove on the land. The amount of reduction in pressure values depends on the volume of the groove, not on the aspect ratio of the groove. Addition of a central groove reduces the pressures, rigidity developed in squeeze film land, and forces generated by squeeze film damper.

Linear Force Coefficients for Squeeze-Film Dampers

1983 ◽  
Vol 105 (3) ◽  
pp. 326-334 ◽  
Author(s):  
A. Z. Szeri ◽  
A. A. Raimondi ◽  
A. Giron-Duarte
Keyword(s):  
Reynolds Number ◽  
Diameter Ratio ◽  
Linear Velocity ◽  
Squeeze Film ◽  
Viscous Damper ◽  
Squeeze Film Damper ◽  
Force Coefficients ◽  
Squeeze Film Dampers ◽  
Linear Force

This paper presents a simplifed analysis of viscous squeeze-film damper behavior. It makes use of the notation of averaged inertia and calculates linear velocity and inertia coeffcients. These coefficients are shown to be accurate at practical values of the length/diameter ratio and the gap Reynolds number of the viscous damper.

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.

scholarly journals A computational fluid dynamics investigation of the segmented integral squeeze film damper

2019 ◽  
Vol 254 ◽  
pp. 08005 ◽  
Author(s):  
Petr Ferfecki ◽  
Jaroslav Zapoměl ◽  
Marek Gebauer ◽  
Václav Polreich ◽  
Jiří Křenek
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Ansys Cfx ◽  
Squeeze Film Dampers ◽  
Tilting Pad ◽  
Vibration Attenuation ◽  
Tilting Pad Journal Bearing

Rotor vibration attenuation is achieved with damping devices which work on different, often mutually coupled, physical principles. Squeeze film dampers are damping devices that have been widely used in rotordynamic applications. A new concept of a 5-segmented integral squeeze film damper, in which a flexure pivot tilting pad journal bearing is integrated, was investigated. The damper is studied for the eccentric position between the outer and inner ring of the squeeze film land. The ANSYS CFX software was used for solving the pressure and velocity distribution. The development of the complex three-dimensional computational fluid dynamics model of the squeeze film damper, learning more about the effect of the forces in the damper, and the knowledge about the behaviour of the flow are the principal contributions of this article.

scholarly journals The Damping Capacity of a Sealed Squeeze Film Bearing

1985 ◽  
Vol 107 (3) ◽  
pp. 411-418 ◽  
Author(s):  
M. M. Dede ◽  
M. Dogan ◽  
R. Holmes
Keyword(s):  
Theoretical Model ◽  
Gas Turbine ◽  
Squeeze Film ◽  
Damping Capacity ◽  
Test Rig ◽  
Squeeze Film Damper ◽  
Aero Engine

The purpose of this paper is to establish a theoretical model to represent a sealed squeeze-film damper bearing and to assess it against results from a test rig, simulating the essential features of a medium-sized gas turbine aero engine.

Validation of a squeeze-film-damper test rig by using multibody cosimulation

2014 ◽  
Vol 34 (3) ◽  
pp. 243-257 ◽  
Author(s):  
Steffen Jäger ◽  
Sabrina Vogel
Keyword(s):  
Squeeze Film ◽  
Test Rig ◽  
Squeeze Film Damper

scholarly journals Squeeze-Film Damper Technology: Part 1 — Prediction of Finite Length Damper Performance

1983 ◽  
Author(s):  
J. W. Lund ◽  
A. J. Smalley ◽  
J. A. Tecza ◽  
J. F. Walton
Keyword(s):  
Finite Length ◽  
Gas Turbines ◽  
Squeeze Film ◽  
Fluid Inertia ◽  
Inertia Effects ◽  
Strongly Coupled ◽  
Squeeze Film Damper ◽  
Rotor Systems ◽  
Squeeze Film Dampers ◽  
Calculation Results

Squeeze-film dampers are commonly used in gas turbine engines and have been applied successfully in a great many new designs, and also as retrofits to older engines. Of the mechanical components in gas turbines, squeeze-film dampers are the least understood. Their behavior is nonlinear and strongly coupled to the dynamics of the rotor systems on which they are installed. The design of these dampers is still largely empirical, although they have been the subject of a large number of past investigations. To describe recent analytical and experimental work in squeeze-film damper technology, two papers are planned. This abstract outlines the first paper, Part 1, which concerns itself with squeeze-film damper analysis. This paper will describe an analysis method and boundary conditions which have been developed recently for modelling dampers, and in particular, will cover the treatment of finite length, feed and drain holes and fluid inertia effects, the latter having been shown recently to be of great importance in predicting rotor system behavior. A computer program that solves the Reynolds equation for the above conditions will be described and sample calculation results presented.

scholarly journals Imbalance Response of a Test Rotor Supported on Squeeze Film Dampers

1998 ◽  
Vol 120 (2) ◽  
pp. 397-404 ◽  
Author(s):  
L. San Andre´s ◽  
D. Lubell
Keyword(s):  
Chaotic Behavior ◽  
Nonlinear Behavior ◽  
Theoretical Models ◽  
Forced Response ◽  
Analytical Models ◽  
Squeeze Film ◽  
Test Rig ◽  
Critical Speeds ◽  
Highly Nonlinear ◽  
Squeeze Film Dampers

Squeeze film dampers (SFDs) provide vibration attenuation and structural isolation to aircraft gas turbine engines which must be able to tolerate larger imbalances while operating above one or more critical speeds. Rotor-bearing-SFD systems are regarded in theory as highly nonlinear, showing jump phenomena and even chaotic behavior for sufficiently large levels of rotor imbalance. Yet, few experimental results of practical value have verified the analytical predictions. A test rig for measurement of the dynamic forced response of a three-disk rotor (45 kg) supported on two cylindrical SFDs is described. The major objective is to provide a reliable data base to validate and enhance SFD design practice and to allow a direct comparison with analytical models. The open-ends SFD are supported by four-bar centering structures, each with a stiffness of 3.5 MN/m. Measured synchronous responses to 9000 rpm due to various imbalances show the rotor-SFD system to be well damped with amplification factors between 1.6 and 2.1 while traversing cylindrical and conical modes critical speeds. The rotor amplitudes of motion are found to be proportional to the imbalances for the first mode of vibration, and the damping coefficients extracted compare reasonably well to predictions based on the full-film, open-ends SFD. Tight lip (elastomeric) seals contribute greatly to the overall damping of the test rig. Measured dynamic pressures at the squeeze film lands are well above ambient values with no indication of lubricant dynamic cavitation as simple theoretical models dictate. The measurements show absence of nonlinear behavior of the rotor-SFD apparatus for the range of imbalances tested.

Application of CFD Analysis for Rotating Machinery: Part 1 — Hydrodynamic, Hydrostatic Bearings and Squeeze Film Damper

2003 ◽  
Author(s):  
Zenglin Guo ◽  
Toshio Hirano ◽  
R. Gordon Kirk
Keyword(s):  
Traditional Method ◽  
Reasonable Agreement ◽  
Pressure Field ◽  
Squeeze Film ◽  
Cfd Analysis ◽  
Complex Flow ◽  
Static And Dynamic Characteristics ◽  
Squeeze Film Damper ◽  
Squeeze Film Dampers ◽  
Machinery Part

The traditional method for bearing and damper analysis usually involves a development of rather complicated numerical calculation programs that may just focus on a simplified and specific physical model. The application of the general CFD codes may make this analysis available and effective where complex flow geometries are involved or when more detailed solutions are needed. In this study, CFX-TASCflow is employed to simulate various fixed geometry fluid-film bearing and damper designs. Some of the capabilities in CFX-TASCflow are applied to simulate the pressure field and calculate the static and dynamic characteristics of hydrodynamic, hydrostatic and hybrid bearings as well as squeeze film dampers. The comparison between the CFD analysis and current computer programs used in industry has been made. The results show reasonable agreement in general. Some of possible reasons for the differences are discussed. It leaves room for further investigation and improvement on the methods of computation.

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