Results 191 to 200 of about 3,492 (237)

Experimental Observation of Cavitating Squeeze-Film Dampers

Journal of Tribology, 1987
This paper presents the results of an experimental investigation intended to observe cavitation in squeeze-film bearing dampers representative of those commonly found in aircraft gas turbine engines. Two different squeeze-film damper geometries were tested with both high-speed motion pictures and stroboscopic video recordings acquired at speeds up to ...
J. F. Walton, J. A. Walowit, E. S. Zorzi, J. Schrand   +3 more
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Equivalent Linearization of a Squeeze Film Damper

Journal of Vibration and Acoustics, 1986
In this paper, the equivalent linearization of an intershaft squeeze film damper in a two shaft engine system is investigated. The two shaft centers at the damper position are assumed to move in different elliptical offset orbits and at synchronous frequency with the unbalanced rotor (e.g., the high pressure rotor).
Songqi Chen, Shengpei Liu
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A Numerical Study of Squeeze Film Dampers

Volume 7B: Structures and Dynamics, 2013
Squeeze film dampers (SFDs) are used in the high speed turbomachinery industry as a means to reduce vibration amplitude, provide damping, and improve dynamic stability of the rotor bearing system. Past numerical studies analyzing SFDs, have been computationally expensive and time consuming.
Praneetha Boppa, Gerald L. Morrison, Aarthi Sekaran   +2 more
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Linear Force Coefficients for Squeeze-Film Dampers

Journal of Lubrication Technology, 1983
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.
A. Z. Szeri, A. A. Raimondi, A. Giron-Duarte   +2 more
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Modeling Finite Squeeze Film Dampers

Volume 4: Turbo Expo 2002, Parts A and B, 2002
Most closed form solutions of Reynolds’ equation assume either a short bearing approximation or a long bearing approximation. These closed form approximations are used in rotordynamic simulation applications, otherwise a Finite Difference solution of Reynolds’ equation would be prohibitively time consuming.
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Optimal Design of Centered Squeeze Film Dampers

13th Biennial Conference on Mechanical Vibration and Noise: Rotating Machinery and Vehicle Dynamics, 1991
Abstract A two degree-of-freedom model, consisting of a rigid rotor supported on rigid bearings which are in turn supported on squeeze film dampers, is considered. Isotropic centering springs are assumed resulting in a steady synchronous centered circular response for the rotor. The resulting nonlinear system is modeled in nondimensional
Nataraj, C., Ashrafiuon, Hashem.
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Squeeze Film Damper Suppression of Thermal Bow: Morton Effect Instability

Volume 10B: Structures and Dynamics, 2020
Abstract The Morton Effect (ME) is a synchronous vibration problem in turbomachinery caused by the non-uniform viscous heating around the journal circumference, and its resultant thermal bow and ensuing synchronous vibration. This paper treats the unconventional application of the SFD for the mitigation of ME-induced vibration ...
Dongil Shin, Alan B. Palazzolo, Xiaomeng Tong   +2 more
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Fluid Inertia Forces in Squeeze Film Dampers

13th Biennial Conference on Mechanical Vibration and Noise: Rotating Machinery and Vehicle Dynamics, 1991
Abstract Fluid inertia forces in Squeeze Film Dampers (SFDs) are obtained for short and long dampers using an energy approximation based on the assumption that the velocity profiles with inertia are the same as those for an inertialess fluid.
A. El-Shafei, S. M. Crandall
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Floating ring squeeze film damper: theoretical analysis

Tribology International, 2000
Abstract The non-linear characteristics of squeeze film dampers can frequently promote multi-stable operation, e.g. jump, or aperiodic response in rotating machinery. Such undesirable operation can sometimes be avoided in rigid rotor systems by replacing the rigidly supported damper housing with a flexibly mounted rigid ring or ‘floating’ ring, but ...
M.A Rezvani, E.J Hahn
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Nonsynchronous Motion of Squeeze Film Damper Systems

Journal of Tribology, 1987
The nonsynchronous motion of a rigid rotor-squeeze film damper system was investigated. This research classifies the phenomenon of the system with perfectly preloaded centering springs, reveals its existence conditions, and analyzes the system’s topological structures associated with the phenomenon.
Xuehai Li, Dean L. Taylor
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