Numerical and experimental analysis of the first-and second-mode instability in a rotor-bearing system

Ma, Hui; Li, Hui; Niu, Heqiang; Song, Rongfang; Wen, Bangchun

doi:10.1007/s00419-013-0815-9

Cited by 40 publications

(24 citation statements)

References 34 publications

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“…Among other dynamic characteristics according to the features of the rotor systems, most of the failure types may exist as harmonic patterns; an occurrence breathing crack in the sense that it has basically 2X frequency due to the rotor weight [2]; a misalignment with an unbalance causes basically 1X and 2X frequencies [3,4]; sub-or super-harmonics such as aero-elastic or blade tuned vibration effects [5], rotor-stator rubbing fault [6] and oil whirl or whip [7][8][9], etc. Accordingly, the harmonic analysis for operational conditions of the rotor systems is prerequisite for clear identification of the cause of failures.…”

Section: Introductionmentioning

confidence: 99%

“…They have been clearly investigated and understood by introducing the frequency domain approach [11,14] which is physically definite in the sense that the solution can be directly obtained from the original equation of motion using the modulation of coordinates. The time domain approach using Floquet theory [7,[11][12][13] is strictly mathematical and rigorous to reach the frequency responses starting from the notion of the decomposition of transition matrix.…”

Section: Introductionmentioning

confidence: 99%

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Complex harmonic modal analysis of rotor systems

Han

2015

J Mech Sci Technol

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Complex harmonic analysis for rotor systems has been proposed from the strict complex modal analysis based upon Floquet theory. In this process the harmonic balance method is adopted, effectively associated with conventional eigenvalue analysis. Also, the harmonic coefficients equivalent to dFRFs in harmonic mode has been derived in practice. The modes are classified from identifying the modal characteristics, and the adaptation of harmonic balance method has been proven by comparing the results of the stability analyses from Floque theory and the eigen analysis. The modal features of each critical speed are depicted in quantitatively and qualitatively by showing that the strengths of each component of the harmonic coefficients are estimated from the order of magnitude analysis according to their harmonic patterns. This effectiveness has been verified by comparing with the numerical solutions.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Complex harmonic modal analysis of rotor systems

Han

2015

J Mech Sci Technol

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“…The different types of vibration problems of rotor system have been studied [1][2][3][4][5][6][7][8][9][10]. For example, Ying J.…”

Section: Introductionmentioning

confidence: 99%

Vibration modes of the rotor system of turbocharger with floating-ring bearing

Li¹,

Zhang²,

Zhang³

et al. 2016

J. vibroeng.

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In this paper, in order to investigate the natural modes of the rotor system of turbocharger, the analytical model of floating-ring bearing, the FEM and modal test technology were employed. Firstly, based on Reynolds equations of the dynamic oil layer of floating-ring bearing, the oil layer pressure was obtained by using the finite difference algorithm. Then the stiffness coefficients and damping coefficients were calculated by using integration method. Next the FEM model of rotor system with supporting stiffness of floating-ring bearings was established. Then the natural modes of rotor system were simulated with considering the oil layer stiffness of the floating-ring bearings and the rotor's rotating speeds. Lastly, the natural modes were identified with modal test technology and furthermore the FEM calculation results were verified. The investigation shows that the oil layer stiffness of the floating-ring bearings and rotating speeds of the rotor have great influences on vibration modes of the rotor system.

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“…is used to solute the complicated nonlinear equations. The algorithm is unconditionally convergent as the values of parameters b ø 1/4 and g ø 1/2 40. The bifurcation diagrams, waterfall diagrams, frequency spectrums, rotor orbits, and Poincare´maps are used to illustrate the nonlinear dynamic behaviors of the rotor/seal-DVA system.The parameters of the rotor/seal system are as follows.…”

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confidence: 99%

Nonlinear dynamic behavior and stability of a rotor/seal system with the dynamic vibration absorber

Niu

Yao

et al. 2019

Advances in Mechanical Engineering

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The dynamic vibration absorbers have been applied to attenuate the critical or unbalanced vibration but may create the fluid-induced vibration instability in the rotor/seal system. The major purpose of this study is devoted to the effects of the dynamic vibration absorber on the nonlinear dynamic behavior and stability of the fluid-induced vibration in the rotor/seal system. The dynamic vibration absorber is attached on the shaft in the perpendicular directions. The model of the rotor/seal-dynamic vibration absorber system is established as the modified Jeffcott rotor system, and Muszynska nonlinear seal force is applied. The numerical method is used for the dynamic behavior analysis. The effects of the natural frequency and damping ratio of the dynamic vibration absorber on the dynamic behavior are discussed. The stability of the rotor/seal-dynamic vibration absorber system is judged by the eigenvalue theory. The variations of the instability threshold with the parameters of the dynamic vibration absorber are obtained. The results show that the instability threshold and instability vibration frequency are changed by the dynamic vibration absorber. The parameters of the dynamic vibration absorber must be selected carefully to avoid reducing the instability threshold and causing the instability vibration to occur in advance when the dynamic vibration absorber is applied to attenuate the critical or unbalanced vibration of the rotor/seal system.

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Numerical and experimental analysis of the first-and second-mode instability in a rotor-bearing system

Cited by 40 publications

References 34 publications

Complex harmonic modal analysis of rotor systems

Complex harmonic modal analysis of rotor systems

Vibration modes of the rotor system of turbocharger with floating-ring bearing

Nonlinear dynamic behavior and stability of a rotor/seal system with the dynamic vibration absorber

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