Force Coefficients for Open-Ended Squeeze-Film Dampers Executing Small-Amplitude Motions About an Off-Center Equilibrium Position

Andrés, Luis San; Vance, John M.

doi:10.1080/05698198708981732

Cited by 20 publications

(8 citation statements)

References 19 publications

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“…Different theoretical studies have investigated the modeling and the formulating of the lubricant fluid inertia effects in SFDs. These theoretical studies provide different insights into the lubricant inertia, including: closed-form analytical solutions for the SFD fluid equations [11][12][13], numerical procedures to solve the SFD pressure distribution and reaction forces [14][15][16][17][18], the force coefficients that represent the direct and cross-coupled SFD inertia and damping [19][20][21][22], and SFD expressions for limiting damper geometries (i.e. long and short bearing approximations) [23,24].…”

Section: Introductionmentioning

confidence: 99%

The effect of lubricant inertia on fluid cavitation for high-speed squeeze film dampers

Fan¹,

Hamzehlouia²,

Behdinan³

2017

J. vibroeng.

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This work studies the effect of lubricant inertia on the fluid cavitation for partially sealed high-speed squeeze film dampers (SFDs) executing small amplitude circular-centered orbits (CCOs). The lubricant cavitation is modeled by both the Elrod algorithm and the Gumbel's cavitation boundary condition to provide the comparison between the most common lubricant cavitation models. Additionally, the fluid inertia is integrated by adapting a finite-length SFD model for partially sealed dampers. The integrated SFD model is incorporated into a numerical simulation model and the results are validated by comparison with experimental data. The results of the analysis demonstrate that the fluid inertia effects significantly extend the cavitation region and influence the cavitation onset and the film reformation.

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Section: Introductionmentioning

confidence: 99%

The effect of lubricant inertia on fluid cavitation for high-speed squeeze film dampers

Fan¹,

Hamzehlouia²,

Behdinan³

2017

J. vibroeng.

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“…Moreover, they have determined the force coefficients for long and short SFDs. San Andres et al [9][10][11][12] have determined SFD force coefficients for short and long bearing geometries and extended the application of these force coefficients to finite length bearings by applying a leakage coefficient. Hashimoto [13] has developed analytical pressure expressions for infinitely long journal bearings with turbulence and inertia effects.…”

Section: Introductionmentioning

confidence: 99%

“…Tichy [22] has studied the effect of small amplitude CCOs for viscoelastic fluids, showing the significant effect of fluid inertia on the fluid film reaction forces, even at moderate Reynolds numbers. San Andres and Vance [9,11] have further emphasized the significant effect of fluid inertia on dynamic performance of squeeze film dampers executing small amplitude CCOs by representing the effect of fluid inertia on SFD force coefficients for both central and off-centered motions of the journal center.…”

Section: Introductionmentioning

confidence: 99%

Squeeze Film Dampers Executing Small Amplitude Circular-Centered Orbits in High-Speed Turbomachinery

Hamzehlouia

Behdinan

2016

International Journal of Aerospace Engineering

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This work represents a pressure distribution model for finite length squeeze film dampers (SFDs) executing small amplitude circular-centered orbits (CCOs) with application in high-speed turbomachinery design. The proposed pressure distribution model only accounts for unsteady (temporal) inertia terms, since based on order of magnitude analysis, for small amplitude motions of the journal center, the effect of convective inertia is negligible relative to unsteady (temporal) inertia. In this work, the continuity equation and the momentum transport equations for incompressible lubricants are reduced by assuming that the shapes of the fluid velocity profiles are not strongly influenced by the inertia forces, obtaining an extended form of Reynolds equation for the hydrodynamic pressure distribution that accounts for fluid inertia effects. Furthermore, a numerical procedure is represented to discretize the model equations by applying finite difference approximation (FDA) and to numerically determine the pressure distribution and fluid film reaction forces in SFDs with significant accuracy. Finally, the proposed model is incorporated into a simulation model and the results are compared against existing SFD models. Based on the simulation results, the pressure distribution and fluid film reaction forces are significantly influenced by fluid inertia effects even at small and moderate Reynolds numbers.

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“…Effects of the fluid inertia, which was neglected in the Reynolds' equation, but existed in those fluid momentum equations, were approached by Ballal and Rivlin [80], San Andres and Vancea [81], Tichy and Bou-Said [82], and Kim and Szeri [83]. Two main methods, the perturbation analysis and the method of averaged inertia, were developed in those analyses.…”

Section: Nonlinear Modeling and Nonlinear Forces Calculationmentioning

confidence: 99%

“…Using the methodology developed by Kirk and Gunter [81] for the short bearing, the pressure profile of the short plain journal bearing is calculated by solving Reynolds' Eq.…”

Section: Short Plain Journal Bearings and Short Squeeze Film Dampersmentioning

confidence: 99%

Transient Analysis of Flexible Rotors with Nonlinear Bearings, Dampers and External Forces

Cao

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General rotor-bearing systems often display nonlinear behavior due to hydrodynamic effects and external nonlinear forces. Linear methods based on finite element methods are the most common methods for performing rotor dynamic analyses. Nonlinear bearing/damping forces are often linearized into equivalent stiffness and damping coefficients. This method often works well for weakly nonlinear systems, but has limits for strongly nonlinear systems. To more accurately describe rotor behavior, transient analysis and nonlinear models are often used. Analytical solutions for Jeffcott rotors with I would also like to thank my committee, Prof. Zongli Lin, Prof. Kent Richard, Prof. John Thacker and Prof. Costin Untaroiu, for their support, input and encouragement on the work of my research. I would also like to thank Prof. Pradip N. Sheth, who encouraged me to join the graduate program. It was pleasure learning and working with him.

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Force Coefficients for Open-Ended Squeeze-Film Dampers Executing Small-Amplitude Motions About an Off-Center Equilibrium Position

Cited by 20 publications

References 19 publications

The effect of lubricant inertia on fluid cavitation for high-speed squeeze film dampers

The effect of lubricant inertia on fluid cavitation for high-speed squeeze film dampers

Squeeze Film Dampers Executing Small Amplitude Circular-Centered Orbits in High-Speed Turbomachinery

Transient Analysis of Flexible Rotors with Nonlinear Bearings, Dampers and External Forces

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