0
Research Papers

Vibration Behavior of Flexible Rotor System Mounted on MR Squeeze Film Damper With Thermal Growth Effect

[+] Author and Article Information
Hamed Ghaednia

Department of Mechanical Engineering,  Amirkabir University of Technology, Hafez Ave., 424, Tehran, Iran

Abdolreza Ohadi1

Department of Mechanical Engineering,  Amirkabir University of Technology, Hafez Ave., 424, Tehran, Irana_r_ohadi@aut.ac.ir

1

Corresponding Author.

J. Vib. Acoust 134(1), 011015 (Dec 30, 2011) (10 pages) doi:10.1115/1.4004682 History: Received September 01, 2010; Revised June 01, 2011; Published December 30, 2011; Online December 30, 2011

Semiactive vibration reduction devices using magnetorheological fluid (MR fluid) have proven to be effective in different engineering applications. MR squeeze film damper (MR-SFD) is one type of such devices that can be used to reduce unwanted vibration in rotary machinery. The behavior of these devices is a function of electric current, which controls the magnetic field in the lubricant and therefore causes the viscosity of MR fluid to be changed. In spite of all researches have been carried out in behavior analysis of different sorts of MR-SFDs, investigations over thermal growth effects on the efficiency of these actuators, in vibration reduction applications, are rare. In this paper, a Magnetorheological squeeze film damper (MR-SFD) has been modeled using two governing equations. First, considering the Bingham model for MR fluid (MRF), a hydrodynamic model has been presented. Second, a thermal model for the system has been modeled and used to calculate the temperature rise in the squeeze film and different damper’s components. Temperature rise in MR-SFD has been considered in this paper as a novel study. Time and frequency domain analysis using Newmark method has been performed over a finite element model of the system consisting of an unbalanced flexible rotor mounted on a pair of MR-SFDs. Obtained results show that the amplitude of rotor’s vibration is not a simple function of electrical current such that, increase in the current cannot guarantee decrease in the value of amplitude. Two major phenomena have been observed during studies; rigid dampers, and generation of new critical speed. The behavior of the rotor is deeply affected by these phenomena. The steady state response of rotor versus rotation velocity is presented for different values of electrical current, which show the effects of temperature and current on the steady state response of rotor. Generally, temperature rise results in inefficiency of MR-SFDs to suppress the vibration of the rotor, especially for rotational velocities near critical speed. Due to temperature rise, appearance of the second critical speed occurs at higher values of electrical current. In addition, it delays the “rigid damper” phenomenon causing rotor response to decrease.

FIGURES IN THIS ARTICLE
<>
Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic view of MR-SFD and coordinates

Grahic Jump Location
Figure 2

(a) Schematic of MR-SFD and its components, (b) the resultant thermal circuit

Grahic Jump Location
Figure 3

Schematic of rotor-damper system

Grahic Jump Location
Figure 4

Time domain analysis for ω=100 rad/s,I=0.0,0.5,1.0,2.0 A

Grahic Jump Location
Figure 5

Time domain analysis for ω=150 rad/s,I=0.0,0.5,1.0,2.0 A

Grahic Jump Location
Figure 6

Time domain analysis for ω=600 rad/s,I=0.0,0.5,1.0,2.0 A

Grahic Jump Location
Figure 7

Frequency behavior of steady state response of rotor, for low electrical currents

Grahic Jump Location
Figure 8

Frequency behavior of steady state response of rotor, for medium electrical currents

Grahic Jump Location
Figure 9

Frequency behavior of steady state response of rotor, for high electrical currents

Grahic Jump Location
Figure 10

Frequency behavior of steady state response of rotor, for different stdies. The comparison between studies is available in this figure.

Grahic Jump Location
Figure 11

(a) Steady state response of rotor versus rotational velocity considering temperature rise in MR-SFD and I=0.0 A (b) steady state temperature of MR-SFD components versus rotational velocity

Grahic Jump Location
Figure 12

Steady state response of rotor versus rotational velocity considering temperature rise in MR-SFD and I=0.85 A

Grahic Jump Location
Figure 13

Steady state response of rotor versus rotational velocity considering temperature rise in MR-SFD and I=2.0 A

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In