Results 201 to 210 of about 3,492 (237)

Stability analysis of intershaft squeeze film dampers

Journal of Sound and Vibration, 1991
Abstract Intershaft squeeze film dampers have been investigated for damping of dual rotor aircraft jet engines. Initial investigations indicated that the intershaft dampers would attenuate the amplitude of the engine vibration and decrease the force transmitted through the intershaft bearing, thereby increasing its life.
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Experimental Investigation of a Simple Squeeze Film Damper

Journal of Engineering for Industry, 1974
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.
H. Andersen, K. K. Thomsen
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Fluid forces in short squeeze-film damper bearings

Tribology International, 1997
Abstract This paper has studied influences of fluid inertia on fluid velocity profiles and provided an axial inertia velocity profile for short squeeze film damper bearings (SFDs) using as a starting point a simplified Navier–Stokes equation. The velocity profile reasonably represents influences of fluid inertia on fluid flow.
Tan Qingchang, Li Wei, Zhang Jun
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Squeeze Film Damper Characteristics for Gas Turbine Engines

Journal of Mechanical Design, 1978
A mathematical model for squeeze film dampers is developed, and the solution results are compared with data from four different test rigs. A special feature of the analysis is the treatment of several different types of end seals and inlets, with inlet feedback included.
R. A. Marmol, J. M. Vance
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Active squeeze film dampers in rotordynamics

2001
Summary: Electro-rheological and magneto-rheological fluids react to electric and magnetic fields respectively undergoing changes in their mechanical characteristics, viscosity and stiffness in particular. Their macroscopic behaviour is represented by the Bingham plastic model.
CARMIGNANI, COSTANTINO, FORTE, PAOLA
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Dynamic characteristics of elastic ring squeeze film damper

Industrial Lubrication and Tribology, 2019
Purpose The purpose of this paper is to present a numerical model to investigate the dynamic behavior and force coefficients of a compact squeeze film damper with dual film clearances adjusted by an elastic ring, known as elastic ring squeeze film damper (ERSFD).
Zhenlin Wang, Zhansheng Liu, Guanghui Zhang   +2 more
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Side clearance effects on squeeze film damper performance

Tribology International, 2000
Computational fluid dynamics has been used to study the influence of end seal clearance and flow path length on the performance of a circular orbiting squeeze film damper with a central circumferential feed groove. Results indicate that to be effective in modifying the damper stiffness and damping characteristics, the axial clearance between the damper
P.Y.P Chen, E.J Hahn
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Stability of Squeeze-Film-Damper Supported Flexible Rotors

Journal of Engineering for Power, 1977
Assuming the short bearing approximation and symmetric motions, the stability of the steady-state synchronous operation of centrally preloaded single-mass flexible rotors supported in squeeze-film bearing dampers is theoretically investigated. The stability regions are depicted over a wide range of system parameters and allow for easy determination of ...
M. D. Rabinowitz, E. J. Hahn
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Rotordynamic Performance of Finite Length Squeeze Film Dampers

Volume 4: Turbo Expo 2003, 2003
A recently developed finite length model of squeeze film dampers is extended and used in predicting the behavior of a rigid rotor supported by squeeze film dampers (SFDs). The model is based on a perturbation solution of Reynolds’ equation. The finite length SFD damping coefficients are presented for various L/R ratios.
A. El-Shafei, A. S. El-Kabbany
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Simple but Accurate Models for Squeeze-film Dampers

2007 IEEE Sensors, 2007
Simple but accurate compact models are derived for squeeze-film dampers having rectangular areas and vibrating in translational or in torsion motion. First, shape functions are derived that enable fast and accurate calculation of the low squeeze number damping coefficient for any aspect ratio of the damper surface. Next, a series-form approximation for
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