0
TECHNICAL PAPERS: Gas Turbines: Structures and Dynamics

Rotor/Seal Experimental and Analytical Study on Full Annular Rub

[+] Author and Article Information
J. J. Yu, P. Goldman, D. E. Bently, A. Muzynska

Bently Rotor Dynamics Research Corporation, 1631 Bently Parkway South, Minden, NV 89423

J. Eng. Gas Turbines Power 124(2), 340-350 (Mar 26, 2002) (11 pages) doi:10.1115/1.1416691 History: Received November 01, 1999; Revised February 01, 2000; Online March 26, 2002
Copyright © 2002 by ASME
Topics: Rotors , Stiffness
Your Session has timed out. Please sign back in to continue.

References

Bently, D. E., 1974, “Forced Subrotative Speed Dynamic Action of Rotating Machinery,” ASME Paper No. 74-PET-16.
Bently, D. E., Grant, J. W., and Goldman, P., 1992, “A ‘Butterfly’ Rub Response,” Bently Rotor Dynamics Research Corporation, BRDRC Report 3.
Muszynska, A., 1984, “Rotor/Seal Full Annular Rub,” Senior Mechanical Engineering Seminar, Bently Nevada Corp., Carson City, NV.
Lawen,  J. L., and Flowers,  G. T., 1999, “Interaction Dynamics Between a Flexible Rotor and an Auxiliary Clearance Bearing,” ASME J. Vibr. Acoust., 121, pp. 183–189.
Yu, J. J., Muszynska, A., and Bently, D. E., 1998, “Dynamic Behavior of Rotor With Full Annular Rub,” Bently Rotor Dynamics Research Corporation, BRDRC Report 7.
Goldman, P., and Bently, D. E., 1998, “Analytical Study of Full Annular Rub,” Bently Rotor Dynamics Research Corporation, BRDRC Report 6.
Muszynska,  A., 1989, “Rotor-to-Stationary Element Rub-Related Vibration Phenomena in Rotating Machinery, Literature Survey,” Shock Vib. Dig., 21, pp. 3–11.
Black,  H. F., 1968, “Interaction of a Whirling Rotor with a Vibrating Stator Across a Clearance Annulus,” J. Mech. Eng. Sci., 10, pp. 1–12.
Ehrich, F. F., 1969, “The Dynamics Stability of Rotor/Stator Radial Rubs in Rotating Machinery,” J. Eng. Ind., pp. 1025–1028.
Lingener, A., 1990, “Experimental Investigation of Reverse Whirl of a Flexible Rotor,” IFToMM Third International Conference on Rotordynamics, Lyon, France, pp. 13–18.
Crandall, S., 1990, “From Whirl to Whip in Rotordynamics,” IFToMM Third International Conference on Rotordynamics, Lyon, France, pp. 19–26.
Childs, D., 1993, Turbomachinery Rotordynamics: Phenomena, Modeling, and Analysis, John Wiley and Sons, New York.

Figures

Grahic Jump Location
Process of generating reverse precessional rub (self-excited vibration, also called “dry whip”) without any outside disturbance. Two-disk rotor/Teflon seal diametral clearance of 500 μm with mass unbalance of 0.5 grams.
Grahic Jump Location
Reverse precesional rub triggered during rundown. One-disk rotor/Teflon seal diametral clearance of 1000 μm with mass unbalance of 1.1 grams.
Grahic Jump Location
Effect of mass unbalance on the starting point where reverse full annular rub occurred without any outside disturbance. One disk rotor, Teflon seal diametral clearance of 250 μm.
Grahic Jump Location
Reverse precessional rub versus time and speed during the whole running process including runup and rundown. One disk rotor, Teflon seal diametral clearance of 750 μm.
Grahic Jump Location
Parameters of slippage of rotor against seal with changes in rotative speed; (a) reverse rub frequency, (b) ratio of reverse frequency to speed, and (c) slip velocity
Grahic Jump Location
Diagram of the rotor/seal system with full annular rub
Grahic Jump Location
Root locus of synchronous response under full annular rub conditions. a=h/Cr=0.2, ς=0.025, Ks/K=0.5. Note that for low value of friction coefficient, f=0.1, the synchronous response is always stable.
Grahic Jump Location
Root locus of synchronous response stability under full annular rub conditions. a=h/Cr=0.2, ς=0.025, Ks/K=0.5,f=0.15. Note that with rotative speed increase the synchronous response experiences transition from being stable to unstable then to stable again.
Grahic Jump Location
Root locus of synchronous response under full annular rub conditions. a=h/Cr=0.2, ς=0.025, Ks/K=0.5. Note that for high value of friction coefficient, f=0.3, the synchronous regime is always unstable.
Grahic Jump Location
Synchronous response for different values of unbalance parameter a with and without rub and its stability
Grahic Jump Location
Synchronous response instability boundaries for different values of f (ς=0.025, p=0.5). Instability leads to self-excited reverse precession. Note destabilizing effect with increase of f.
Grahic Jump Location
Reverse precessional full annular rub frequency
Grahic Jump Location
Rotor/seal full annular rub test rig
Grahic Jump Location
Comparison of rotor lateral responses of the two-disk rotor during runup and rundown tests with/without rubbing, respectively. Teflon seal with diametral clearance of 500 μm; two disks with mass unbalance of 1.1 grams at 0 degree. (a) Direct responses, (b) 1× Bode plots near the seal location. An insert in (a) displays the rotor orbit indicating multicontact intermittent rub.
Grahic Jump Location
Synchronous rub showing that amplitude jumps down during runup and jumps up during rundown. Teflon seal with diametral clearance of 1000 μm; one disk with mass unbalance of 1.6 grams.

Tables

Errata

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