Prediction of Rotor Dynamic Behavior of Synchronous Generators

2015 ◽  
pp. 1797-1808
Author(s):  
J. S. Rao ◽  
Vijendra Gupta ◽  
Prachi Khullar ◽  
D. Srinivas
Keyword(s):  
Dynamic Behavior ◽  
Synchronous Generators ◽  
Rotor Dynamic

Evaluation of bearing’s cavitation effects on the rotor dynamic behavior

2020 ◽  
Vol 77 ◽  
pp. 49-65 ◽  
Author(s):  
Douglas Jhon Ramos ◽  
Gregory Bregion Daniel
Keyword(s):  
Dynamic Behavior ◽  
Rotor Dynamic

scholarly journals Dry Gas Seal Developments and Contamination Prevention

1996 ◽  
Author(s):  
Stan O. Uptigrove ◽  
Paul S. Eakins ◽  
John E. Sears
Keyword(s):  
Dynamic Behavior ◽  
Preventive Measures ◽  
Operating Experience ◽  
Advanced Materials ◽  
Dry Gas Seal ◽  
Industry Standard ◽  
Gas Compression ◽  
Gas Seals ◽  
Materials Used ◽  
Rotor Dynamic

Dry gas seals have become the pipeline industry standard for sealing of centrifugal gas compression equipment. Recent applications have pushed the limits of materials used in their construction from exposure to ever increasing levels of pressure, speed and temperature. This provides the focus for a discussion of recent advances with the use of advanced materials, higher pressure, speed and temperature applications and bidirectional designs. Operating experience has been very favourable, enough to make dry gas seals a preferred standard, but the failures that have occurred raise two fundamental questions. The first concerns the resistance of gas seals to contamination and the second is their influence upon rotor dynamic behavior. Both of these predominant issues are reviewed along with advancements and preventive measures now available to address these concerns.

scholarly journals Synchronous Dynamics of a Coupled Shaft/Bearing/Housing System With Auxiliary Support From a Clearance Bearing: Analysis and Experiment

1997 ◽  
Vol 119 (2) ◽  
pp. 430-435 ◽  
Author(s):  
J. L. Lawen ◽  
G. T. Flowers
Keyword(s):  
Dynamic Behavior ◽  
Magnetic Bearing ◽  
Dynamic Responses ◽  
Housing System ◽  
Vibration Modes ◽  
Simulation Studies ◽  
Flexible Rotor ◽  
Shaft Vibration ◽  
Rotor Dynamic ◽  
Bearing Analysis

This study examines the response of a flexible rotor supported by load sharing between linear bearings and an auxiliary clearance bearing. The objective of the work is to develop a better understanding of the dynamic behavior of a magnetic bearing supported rotor system interacting with auxiliary bearings during a critical operating condition. Of particular interest is the effect of coupling between the bearing/housing and shaft vibration on the rotor-dynamic responses. A simulation model is developed and a number of studies are performed for various parametric configurations. An experimental investigation is also conducted to compare and verify the rotor-dynamic behavior predicted by the simulation studies. A strategy for reducing sychronous shaft vibration through appropriate design of coupled shaft/bearing/housing vibration modes is identified. The results are presented and discussed.

scholarly journals Dynamical Behavior Analysis of Rubbing Rotor System under Asymmetric Oil Film Force

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Youfu Tang ◽  
Feng Lin ◽  
Qian Zou
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Models ◽  
Journal Bearing ◽  
Dynamic Theory ◽  
Dynamical Behavior ◽  
Rotor System ◽  
System Response ◽  
Oil Film ◽  
Rotor Structure ◽  
Rotor Dynamic

Rubbing is one of the most common and significant faults that exist in the rotor system. It exhibits extremely complicated dynamic behavior. Existing dynamic models are primarily based on the symmetrical rotor structure, in which the oil film forces at both ends of support are considered identical. However, in practice, the oil film force may be differently affected by multiple factors (e.g., viscosity of lubricants, the thickness of oil film, and clearance of journal bearing). In this study, a novel dynamic model of the rubbing rotor system under asymmetric oil film force was developed. Furthermore, based on the nonlinear rotor dynamic theory, its dynamic behavior with different parameters was analyzed, and the corresponding chaotic features were extracted. The results indicated that the evolution law of chaotic motion was more complicated, and the chaotic region of system response was obviously wider under the asymmetric oil film force than the symmetrical oil film force.

Development of a Set of Equations for Incorporating Disk Flexibility Effects in Rotordynamic Analyses

1993 ◽  
Vol 115 (2) ◽  
pp. 227-233 ◽  
Author(s):  
G. T. Flowers ◽  
S. G. Ryan
Keyword(s):  
Dynamic Behavior ◽  
Equations Of Motion ◽  
Rotor System ◽  
Rotor Speed ◽  
Disk System ◽  
Rigid Disk ◽  
First Order ◽  
Transverse Vibrations ◽  
Rotor Dynamic ◽  
Sample System

Rotordynamic equations that account for disk flexibility are developed. These equations employ free-free rotor modes to model the rotor system. Only transverse vibrations of the disks are considered, with the shaft/disk system considered to be torsionally rigid. Second-order elastic foreshortening effects that couple with the rotor speed to produce first-order terms in the equations of motion are included. The approach developed in this study is readily adaptable for usage in many of the codes that are currently used in rotordynamic simulations. The equations are similar to those used in standard rigid disk analyses but with additional terms that include the effects of disk flexibility. An example case is presented to demonstrate the use of the equations and to show the influence of disk flexibility on the rotor dynamic behavior of a sample system.

scholarly journals Dynamic Behavior Analysis of Intermediate Bearing-Squeeze Film Dampers-Rotor System under Constant Maneuvering Overload

2021 ◽  
Vol 2021 ◽  
pp. 1-24
Author(s):  
Nan Zheng ◽  
Mo-li Chen ◽  
Gui-Huo Luo ◽  
Zhi-Feng Ye
Keyword(s):  
Dynamic Behavior ◽  
Dynamic Characteristics ◽  
Rotor System ◽  
Squeeze Film ◽  
Nonlinear Dynamic Model ◽  
Maneuvering Flight ◽  
Squeeze Film Dampers ◽  
Frequency Components ◽  
Simulation Results ◽  
Rotor Dynamic

Under the flight maneuvering of an aircraft, the maneuvering load on the rotor is generated, which may induce the change of dynamic behavior of aeroengine rotor system. To study the influence on the rotor dynamic behavior of constant maneuvering overload, a nonlinear dynamic model of bearing-rotor system under arbitrary maneuver flight conditions is presented by finite element method. The numerical integral method is used to investigate the dynamic characteristics of the rotor model under constant maneuvering overload, and the simulation results are verified by experimental works. Based on this, the dynamic characteristics of a complex intermediate bearing-squeeze film dampers- (SFD-) rotor system during maneuvering flight are analyzed. The simulation results indicate that the subharmonic components are amplified under constant maneuvering overload. The amplitude of the combined frequency components induced by the coupling of the inner and outer rotors is weakened. The static displacements of the rotor caused by the additional excitation force are observed. Besides, the period stability of the movement of the rotor deteriorates during maneuver flight. The design of counterrotation of the inner and outer rotors can effectively reduce the amplitude of subharmonic under constant maneuvering overload.

Effect of bump structural friction on the performance of bump foil bearing and rotor dynamic behavior: Experimental study

2018 ◽  
Vol 233 (5) ◽  
pp. 702-711
Author(s):  
Fangcheng Xu ◽  
Yi Sun ◽  
Guanghui Zhang ◽  
Zhansheng Liu
Keyword(s):  
Dynamic Behavior ◽  
Coulomb Friction ◽  
High Speed ◽  
Dynamic Pressure ◽  
Journal Bearings ◽  
Working Fluid ◽  
Coulomb Effect ◽  
Bearing Sleeve ◽  
Lift Off ◽  
Rotor Dynamic

Air foil bearings are a kind of self-acting lubricated bearing, which have potential applications in high-speed turbomachinery. Air foil journal bearings have simple structure that consists of top foil, bump foil, and bearing sleeve, and use gas as working fluid. However, the relative motion of top foil and bump foil, bump foil and bearing sleeve occurs when dynamic pressure is generated as long as there is spinning of shaft. Thus, the friction between each part of bearing should be considered when modeling. Many papers have theoretically shown the effect of Coulomb friction between top foil and top foil, bump foil and bearing sleeve on the static and dynamic performances of air foil journal bearing by developing many bump foil structural models. The results show that this foil structural Coulomb friction can significantly make bump foil stiffer. However, the improvement of the Coulomb friction effect through experiments is quite difficult and there is no study regarding this so far. The purpose of this paper is to certify the Coulomb effect on bearing performance by using experimental method. Two bump foil journal bearings are manufactured with different bearing sleeve surface roughnesses. Foil structure stiffness, bearing lift-off speed, and rotor dynamic behavior supported by two sets of bearings are measured and compared.

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