Effect of external periodic force on self-sustained vibrations of nonsymmetric one disk rotors supported by arbitary length journal bearings

Authors

  • К. В. Аврамов A.N. Podgorny Institute for Mechanical Engineering Problems of NAS of Ukraine, Ukraine
  • А. В. Борисюк National Technical University "Kharkiv Polytechnic Institute", Ukraine

Keywords:

asymmetrical one disk rotor, arbitrary length journal bearings, forced vibrations, self-sustained vibrations, finite-element procedure, almost periodic motions

Abstract

Nonlinear dynamics of one disk elastic rotor is treated. The shaft is attached in two arbitrary length journal bearings. Unbalance between disk center mass and point of disk attaching to the shaft takes place. The forced vibrations occur due to this unbalance, which always present in a disk. The self-sustained vibrations caused by interaction between fluid film and journal. Nonlinear mathematical model of interaction of forced vibrations and self-sustained vibrations in onedisk elastic rotors is treated. Finite element procedure is used to analyze forces of oil film. The forces of the journal bearings are calculated if form of power series with respect to the generalized displacements and the velocities of the journal. The results of nonlinear analysis of rotor dynamics are presented on frequency responses. The region of almost periodic vibrations is calculated. Both periodic monoharmonic vibrations and the almost periodic motions are observed in the above-mentioned frequency range.

Author Biography

К. В. Аврамов, A.N. Podgorny Institute for Mechanical Engineering Problems of NAS of Ukraine

Doctor of Technical Sciences

References

Zhang X. Y. (1992) On site testing and analysis of the oil whirl phenomena in national made 200MW stream turbine generator systems. Power Industry 12: 32-37

Legrand M., Jiang D., Pierre C., Shaw S.W. (2004) Nonlinear normal modes of a rotating shaft based on the Invariant Manifold Method. International Journal of Rotating Machinery 10: 319-335

Avramov K.V., Borysiuk O. V. (2011) Nonlinear Dynamics of One Disk Asymmetrical Rotor Supported by Two Journal Bearings. Nonlinear Dynamics Vol.67, №2: 1201-1219

Avramov K.V., Mihlin Yu.V. (2013) Review of applications of nonlinear normal modes for vibrating mechanical systems. Applied Mechanical Reviewer 65 (2) (20 pages) doi:10.1115/1.4023533

Muszynska A. (1986) Whirl and whip-rotor/ bearing stability problems. Journal of Sound and Vibration 110: 443-462

Muszynska A. (1988) Stability of whirl and whip in rotor/ bearing systems. Journal of Sound and Vibration 127: 49-64

Adiletta G., Guido A.R., Rossi C. (1997) Nonlinear dynamics of a rigid unbalanced rotor in journal bearing. Part I: Theoretical Analysis. Nonlinear Dynamics 14: 57-87

Adiletta G., Guido A.R., Rossi C. (1996) Chaotic motions of a rigid rotor in short journal bearings. Nonlinear Dynamics 10: 251-269

Avramov K.V. (2010) Asymptotic analysis of the forced vibrations of a one disk rotor on a nonlinear flexible base. Proceedings of Institution of Mechanical Engineers. Part C. Journal of Mechanical Engineering Science 224: 1593-1605

Avramov K.V., Borysiuk O. (2013) Self-sustained vibrations of one dіsk rotor in two arbitrary length journal bearing. Mechanism and Machine Theory 70: 474-486

Borysiuk O.V., Avramov K.V. (2011) Analysis of nonlinear forces acting on rotor shaft in journal bearings. J. of Mechanical Engineering Vol.1, №3: 48–52 (in Russian)

Avramov K. V., Mihlin Yu.V. (2010) Nonlinear dynamics of elastic systems. Regular and Chaotic Dynamics, Moscow–Izhevsk (in Russian)

Subbiah R. (1985) Dynamic Behavior of Rotor Systems with a Comprehensive Model for the Hydrodynamic Bearing Supports Using Modal Analysis and Testing. PhD thesis, Department of Mechanical Engineering, Concordia University, Montreal, Canada

Published

2013-08-29

Issue

Section

Dynamics and Strength of Machines