Dynamic Analysis of a Flexible Rotor Supported on Two Turbulent Model Journal Bearings with Micropolar Fluid Lubrication

2014 ◽  
Vol 592-594 ◽  
pp. 1386-1390
Author(s):  
Sushant Bhatia ◽  
Jaideep Gupta
Keyword(s):  
Dynamic Analysis ◽  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Journal Bearings ◽  
Flexible Rotor ◽  
Wide Range ◽  
Dimensional Parameters ◽  
Rotor Center ◽  
Nonsynchronous Vibrations ◽  
Tangential Directions

This paper presents the complex dynamic analysis of a flexible rotor–bearing system supported by two turbulent micropolar fluid film journal bearings under nonlinear suspension. The Modified Reynolds equation based on the assumptions of turbulent flow and the micropolar parameters has been considered. The system considers Short bearing approximation to simplify the numerical computations. The pressure distribution thus obtained is used to find out the resulting forces about the journal center in the radial and tangential directions. The Non-dimensional dynamic equations are derived considering appropriate non dimensional parameters and solved using MATLAB for a wide range of non-dimensional speed ratios. Plots of the journal center trajectories and rotor center trajectories are obtained. The results show that the system undergoes undesirable nonsynchronous vibrations due to bearing center displacement. Micropolar fluid is found to stabilize the system even when the flow of the system becomes turbulent. The study presented enhances the understanding of the nonlinear dynamics of turbulent journal bearings with respect to dimensionless parameters.

Bifurcation Analysis of Self-Acting Gas Journal Bearings

2001 ◽  
Vol 123 (4) ◽  
pp. 755-767 ◽  
Author(s):  
Cheng-Chi Wang ◽  
Cha’o-Ku`ang Chen
Keyword(s):  
Dynamic Behavior ◽  
Reynolds Equation ◽  
Rotational Velocity ◽  
Power Spectra ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Finite Differences Method ◽  
Subharmonic Response ◽  
Rotor Center ◽  
Rotor Mass

This paper studies the bifurcation of a rigid rotor supported by a gas film bearing. A time-dependent mathematical model for gas journal bearings is presented. The finite differences method and the Successive Over Relation (S.O.R) method are employed to solve the Reynolds’ equation. The system state trajectory, Poincare´ maps, power spectra, and bifurcation diagrams are used to analyze the dynamic behavior of the rotor center in the horizontal and vertical directions under different operating conditions. The analysis shows how the existence of a complex dynamic behavior comprising periodic and subharmonic response of the rotor center. This paper shows how the dynamic behavior of this type of system varies with changes in rotor mass and rotational velocity. The results of this study contribute to a further understanding of the nonlinear dynamics of gas film rotor-bearing systems.

Nonlinear Dynamic Analysis of a Flexible Rotor Supported by Externally Pressurized Porous Gas Journal Bearings

2002 ◽  
Vol 124 (3) ◽  
pp. 553-561 ◽  
Author(s):  
Cheng-Chi Wang ◽  
Cheng-Ying Lo ◽  
Cha’o-Kuang Chen
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
Nonlinear Dynamic Analysis ◽  
Power Spectra ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Flexible Rotor ◽  
Bearing Number ◽  
Rotor Mass

This paper studies the nonlinear dynamic analysis of a flexible rotor supported by externally pressurized porous gas journal bearings. A time-dependent mathematical model for externally pressurized porous gas journal bearings is presented. The finite difference method and the Successive Over Relation (S.O.R.) method are employed to solve the modified Reynolds’ equation. The system state trajectory, Poincare´ maps, power spectra, and bifurcation diagrams are used to analyze the dynamic behavior of the rotor and journal center in the horizontal and vertical directions under different operating conditions. The analysis reveals a complex dynamic behavior comprising periodic and quasi-periodic response of the rotor and journal center. This paper shows how the dynamic behavior of this type of system varies with changes in rotor mass and bearing number. The results of this study contribute to a further understanding of the nonlinear dynamics of gas-lubricated, externally pressurized, porous rotor-bearing systems.

Cyclic Squeeze Films in Micropolar Fluid Lubricated Journal Bearings

1976 ◽  
Vol 98 (3) ◽  
pp. 412-417 ◽  
Author(s):  
J. Prakash ◽  
P. Sinha
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Loading ◽  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Detailed Consideration ◽  
Sinusoidal Load ◽  
Fluid Theory ◽  
Curve Form

The Reynolds equation for the general case of dynamic loading is derived for fluid suspensions, using the micropolar fluid theory. Detailed consideration is given to the dynamic behavior of squeeze films in journal bearings under a fluctuating load with no journal rotation. The characteristics of an infinitely long journal bearing under a cyclic sinusoidal load are shown in curve form, so as to elaborate the micropolar effects.

Non-linear dynamic analysis of a flexible rotor supported by self-acting gas journal bearings

2004 ◽  
Vol 218 (12) ◽  
pp. 1527-1538 ◽  
Author(s):  
C-C Wang ◽  
M-J Jang ◽  
C-K Chen
Keyword(s):  
Reynolds Equation ◽  
Dynamic Behaviour ◽  
Rotational Velocity ◽  
Power Spectra ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Flexible Rotor ◽  
Non Linear ◽  
Subharmonic Response ◽  
Rotor Mass

This paper studies the bifurcation of a flexible rotor supported by gas film bearings. A time dependent mathematical model for gas journal bearings is presented. The finite difference method, with the successive overrelation method (SOR), is employed to solve the Reynolds equation. The system state trajectory, Poincare maps, power spectra and bifurcation diagrams are used to analyse the dynamic behaviour of the rotor and journal centre in the horizontal and vertical directions under different operating conditions. The analysis reveals a complex dynamic behaviour comprising periodic and subharmonic response of the rotor and journal centre. This paper shows how the dynamic behaviour of this type of system varies with changes in rotor mass and rotational velocity. The results of this study contribute to a further understanding of the non-linear dynamics of gas film rotor-bearing systems.

Dynamic Loading of Micropolar Fluid Lubricated Short Journal Bearings

1981 ◽  
Vol 23 (1) ◽  
pp. 37-44
Author(s):  
C. Singh ◽  
P. Sinha
Keyword(s):  
Micropolar Fluid ◽  
Effective Viscosity ◽  
Reynolds Equation ◽  
Dynamic Behaviour ◽  
Journal Bearing ◽  
Constant Load ◽  
Journal Bearings ◽  
Detailed Consideration ◽  
Dynamically Loaded ◽  
Sinusoidal Load

Dynamically loaded bearings in which the load alternates or rotates are studied in this paper. The Reynolds equation for the general case of a dynamically loaded infinitely short bearing is derived, where the lubricant is assumed to be micropolar. Detailed consideration is given to the dynamic behaviour of squeeze films in a short journal bearing under a sinusoidal load with no journal rotation. Various bearing characteristics are calculated, assuming a full film to exist. The micropolarity of the fluid results in more resistance to journal motion, thereby allowing smaller eccentricities for a constant load. The overall conclusion of this study is an increase in the effective viscosity due to the micropolarity of the lubricant. This theory may find application in lubrication when additives are used.

Analysis of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta
Keyword(s):  
Reynolds Equation ◽  
Theoretical Study ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Constant Flow ◽  
The Finite Element Method ◽  
Lubricant Flow ◽  
Wide Range ◽  
Flow Valve

This paper presents a theoretical study of the performance characteristics of a constant flow valve compensated multirecess hydrostatic journal bearings operating with micropolar lubricant. The finite element method and iterative procedure have been used to solve the modified Reynolds equation governing the micropolar lubricant flow in the bearing. The performance characteristics are presented for a wide range of nondimensional load, lubricant flow, and micropolar parameters. It has been observed that the micropolar parameters significantly influence the performance characteristics of the bearing.

Sign in / Sign up

Export Citation Format

Share Document