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Case Studies of Self-excited Vibration of Rotor Stability Problems

  • Osami MatsushitaEmail author
  • Masato Tanaka
  • Masao Kobayashi
  • Patrick Keogh
  • Hiroshi Kanki
Chapter
  • 34 Downloads
Part of the Mathematics for Industry book series (MFI)

Abstract

Frequencies associated with self-excited vibrations are, in most cases, the natural frequencies of the system. The natural frequencies are not proportional to the rotational speed. Therefore, self-excited vibration is a form of non-synchronous vibration. In rotor systems, the lowest natural frequency is often below the rated rotational speed and it may become unstable, hence self-excited vibration is also known as sub-synchronous vibration. This chapter describes various case studies of self-excited vibrations, which are inherent in rotating machinery, as for a journal bearing, seal, centrifugal impeller, and blade for an axial flow machine. Also, the phenomena of internal friction, fluid trapped in a rotor, and rotor contacting with a stator, may produce strong self-excited vibration. While illustrating these unstable phenomena, the cause or mechanism of the instabilities and appropriate solutions are discussed by citing the v_BASE data. In addition, squeeze film dampers, which are used to stabilize the system by adding a damping effect, are explained.

Keywords

Oil whip Oil whirl Labyrinth seal Rotor blade/impeller force (Thomas force) Wachel’s formula Hysteresis whip (Internal damping) Fluid containing rotor Dry friction whip Dry friction whirl Bently–Muszynska model Squeeze film damper 

Copyright information

© Springer Japan KK, part of Springer Nature 2019

Authors and Affiliations

  • Osami Matsushita
    • 1
    Email author
  • Masato Tanaka
    • 2
  • Masao Kobayashi
    • 3
  • Patrick Keogh
    • 4
  • Hiroshi Kanki
    • 5
  1. 1.The National Defense AcademyYokosukaJapan
  2. 2.The University of TokyoTokyoJapan
  3. 3.IHI CorporationYokohamaJapan
  4. 4.University of BathBathUK
  5. 5.Kobe UniversityKobeJapan

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