Results 191 to 200 of about 1,347 (227)

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.
openaire   +1 more source

Nonlinear Response of Short Squeeze Film Dampers

Journal of Lubrication Technology, 1980
This paper considers the methodology of numerical integration for prediction of dynamic response of squeeze film damper systems. A planar rotor carried in a squeeze film damper with linear centering spring is considered. Governing differential equations are expressed in polar coordinates, and fluid forces are obtained from the Ocvirk short bearing ...
D. L. Taylor, B. R. K. Kumar
openaire   +1 more source

An Appraisal of a Proposed Active Squeeze Film Damper

Journal of Tribology, 1991
A theoretical model for an active squeeze film damper (SFD) is introduced. The design makes it possible to change the radial clearance and land length of the SFD by adjusting the position of the damper ring. Expressions for the oil film forces are obtained.
C. Mu, J. Darling, C. R. Burrows
openaire   +1 more source

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
openaire   +1 more source

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
openaire   +1 more source

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.
openaire   +1 more source

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
openaire   +2 more sources

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
openaire   +1 more source

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
openaire   +1 more source

Momentum and Energy Approximations for Elementary Squeeze-Film Damper Flows

Journal of Applied Mechanics, 1993
To provide understanding of the effects of inertia on squeeze-film damper performance, two elementary flow patterns are studied. These elementary flows each depend on a single generalized motion coordinate whereas general planar motions of a damper are described by two independent generalized coordinates.
Crandall, S. H., El-Shafei, A.
openaire   +2 more sources