R. Rashidi; A. Karami mohammadi Karami mohammadi; F. Bakhtiari nejad Bakhtiari nejad
Volume 5, Issue 4 , December 2008, , Pages 145-159
Abstract
This paper presents the effect of preload on nonlinear dynamic behavior of a rigid rotor supported by two-lobe aerodynamic noncircular journal bearing. A finite element method is employed to solve the Reynolds equation in static and dynamical states and the dynamical equations are solved using Runge-Kutta ...
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This paper presents the effect of preload on nonlinear dynamic behavior of a rigid rotor supported by two-lobe aerodynamic noncircular journal bearing. A finite element method is employed to solve the Reynolds equation in static and dynamical states and the dynamical equations are solved using Runge-Kutta method. To analyze the behavior of the rotor center in the horizontal and vertical directions under different operating conditions, the dynamic trajectory, the power spectra, the Poincare maps and the bifurcation diagrams are used. From this study, results show how the complex dynamic behavior of this type of system comprising periodic, -periodic and quasi-periodic responses of the rotor center varies with changes in preload values by considering two bearing aspect ratio. The results of this study contribute to a better understanding of the nonlinear dynamics of two-lobe aerodynamic noncircular journal bearing system.
Asghar Dashti Rahmatabadi
Volume 4, Issue 1 , March 2007, , Pages 33-38
Abstract
This paper presents the effect of preload on static and dynamic performance characteristics of several gas-lubricated noncircular journal bearing configurations. The linearized system approach using finite element method is used to obtain both steady state and dynamic characteristics. The results of ...
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This paper presents the effect of preload on static and dynamic performance characteristics of several gas-lubricated noncircular journal bearing configurations. The linearized system approach using finite element method is used to obtain both steady state and dynamic characteristics. The results of the investigation shows that preload has a significant effect on frictional power loss and the stability margin. It is observed that increased preload, lowers the stability margin while it will increase the amount of power loss in noncircular gas lubricated bearing systems. The results also show that the preload effect on stability margin is more pronounced at lower compressibility numbers.
