Rubbing between rotating and stationary surfaces in turbomachinery can result in catastrophic failures if not caught quickly. Removing the rub impact can then often require time consuming and expensive solutions including field balancing or magnetic bearing systems. However, simple changes in bearing dynamics via bearing and lubricant adjustment could provide for a faster and cheaper alternative. In this work, a three-disk rotor was examined analytically for nonlinear rotordynamic behavior due to an unbalance-driven rub. The rotordynamic solution was obtained using nonlinear and steady state finite element models to demonstrate the effect of the rub impact on the dynamic response of the machine. A thermoelastohydrodynamic (TEHD) model of tilting pad journal bearing performance was also used to study the possible removal of the rub impact by making minor adjustments to bearing parameters including preload, clearance, pad orientation, and lubricant properties. Gas-expanded lubricants (GELs), tunable mixtures of synthetic oil and carbon dioxide that have been proposed as a means to provide control in bearing-rotor systems, were also considered for their possible role in controlling the rub. The TEHD model provided a range of bearing inputs to the rotor models in the form of stiffness and damping coefficients. Results from the rotordynamic analyses included an assessment of critical speeds, peak rotor displacements, and vibration characteristics. Individual bearing parameter adjustments were found to have smaller, though still significant effects on the response of the machine. Overall, it was found that by adjusting a combination of these bearing parameters, the peak displacement of the rotor could be reduced by large enough amounts to remove the rub impact in the machine, hence providing a simple approach to solving rub impact problems in rotating machinery caused by excessive vibration.

References

References
1.
Muszynska
,
A.
,
2005
,
Rotordynamics
,
Taylor & Francis
, Boca Raton, FL.
2.
Muszynska
,
A.
, and
Goldman
,
P.
,
1995
, “
Chaotic Responses of Unbalanced Rotor/Bearing/Stator Systems With Looseness Or Rubs
,”
Chaos, Solitons Fractals
,
5
(
9
), pp.
1683
1704
.10.1016/0960-0779(94)00171-L
3.
Huang
,
Z.
,
Zhou
,
J.
,
Yang
,
M.
, and
Zhang
,
Y.
,
2011
, “
Vibration Characteristics of a Hydraulic Generator Unit Rotor System With Parallel Misalignment and Rub-Impact
,”
Arch. Appl. Mech.
,
81
(
7
), pp.
829
838
.10.1007/s00419-010-0453-4
4.
Sinha
,
S.
,
2005
, “
Non-Linear Dynamic Response of a Rotating Radial Timoshenko Beam With Periodic Pulse Loading at the Free-End
,”
Int. J. Non-Linear Mech.
,
40
(
1
), pp.
113
149
.10.1016/j.ijnonlinmec.2004.05.019
5.
Cao
,
D.
,
Gong
,
X.
,
Wei
,
D.
,
Chu
,
S.
, and
Wang
,
L.
,
2011
, “
Nonlinear Vibration Characteristics of a Flexible Blade With Friction Damping Due to Tip-Rub
,”
Shock Vib.
,
18
(
1–2
), pp.
105
114
.10.1155/2011/425039
6.
Khanlo
,
H.
,
Ghayour
,
M.
, and
Ziaei-Rad
,
S.
,
2011
, “
Chaotic Vibration Analysis of Rotating, Flexible, Continuous Shaft-Disk System With a Rub-Impact Between the Disk and the Stator
,”
Commun. Nonlinear Sci. Numer. Simul.
,
16
(
1
), pp.
566
582
.10.1016/j.cnsns.2010.04.011
7.
Khanlo
,
H.
,
Ghayour
,
M.
, and
Ziaei-Rad
,
S.
,
2012
, “
Bearings Coefficients Effects on Chaotic and Bifurcation Behavior of Flexible Rotor Systems Subjected to Rub-Impact
,”
J. Vibroeng.
,
14
(
2
), pp.
920
942
.http://jve.lt/Vibro/JVE-2012-14-2/JVE-2012-14-2-816-Khanlo.pdf.pdf
8.
Wang
,
J.
,
Zhou
,
J.
,
Dong
,
D.
,
Yan
,
B.
, and
Huang
,
C.
,
2013
, “
Nonlinear Dynamic Analysis of a Rub-Impact Rotor Supported by Oil Film Bearings
,”
Arch. Appl. Mech.
,
83
(
3
), pp.
413
430
.10.1007/s00419-012-0688-3
9.
Barrett
,
L.
,
Gunter
,
E.
, and
Allaire
,
P.
,
1978
, “
Optimum Bearing and Support Damping for Unbalance Response and Stability of Rotating Machinery
,”
ASME J. Eng. Gas Turbines Power
,
100
(
1
), pp.
89
94
.10.1115/1.3446331
10.
Nicholas
,
J.
, and
Kirk
,
R.
,
1979
, “
Selection and Design of Tilting Pad and Fixed Lobe Journal Bearings for Optimum Turborotor Dynamics
,”
Eight Turbomachinery Symposium
,
Texas A&M University
,
College Station
, TX, Nov. 27–29, pp.
43
57
.
11.
Nicholas
,
J.
, and
Kirk
,
R.
,
1982
, “
Four Pad Tilting Pad Bearing Design and Application for Multistage Axial Compressors
,”
ASME J. Tribol.
,
104
(
4
), pp.
523
529
.10.1115/1.3253278
12.
Bhat
,
R.
,
Rao
,
J.
, and
Sankar
,
T.
,
1982
, “
Optimum Journal Bearing Parameters for Minimum Rotor Unbalance Response in Synchronous Whirl
,”
ASME J. Mech. Des.
,
104
(
2
), pp.
339
344
.10.1115/1.3256349
13.
Untaroiu
,
C.
, and
Untaroiu
,
A.
,
2010
, “
Constrained Design Optimization of Rotor-Tilting Pad Bearing Systems
,”
ASME J. Eng. Gas Turbines Power
,
132
(
12
), p.
122502
.10.1115/1.4001811
14.
Zhang
,
Y.
, and
Wang
,
W.
,
2010
, “
The Nonlinear Dynamic Behavior of Double-Disk Isotropic Rotor System With Rub-Impact
,”
Appl. Mech. Mater.
,
34–35
, pp.
1483
1487
.10.4028/www.scientific.net/AMM.34-35.1483
15.
Wang
,
W.
,
Gao
,
J.
,
Zhang
,
Y.
, and
Yao
,
J.
,
2011
, “
Numerical and Experimental Investigation on the Controlling for Rotor-to-Stationary Part Rubbing in Rotating Machinery
,”
ASME
Paper No. GT2011-46250. 10.1115/GT2011-46250
16.
Chang-Jian
,
C.
, and
Chen
,
C.
,
2006
, “
Nonlinear Dynamic Analysis of a Flexible Rotor Supported by Micropolar Fluid Film Journal Bearings
,”
Int. J. Eng. Sci.
,
44
(
15
), pp.
1050
1070
.10.1016/j.ijengsci.2006.06.008
17.
Chang-Jian
,
C.
, and
Chen
,
C.
,
2009
, “
Chaotic Response and Bifurcation Analysis of a Flexible Rotor Supported by Porous and Non-Porous Bearings With Nonlinear Suspension
,”
Nonlinear Anal.: Real World Appl.
,
10
(
2
), pp.
1114
1138
.10.1016/j.nonrwa.2007.12.004
18.
Wang
,
C.
,
2010
, “
Bifurcation and Nonlinear Analysis of a Flexible Rotor Supported by a Relative Short Spherical Gas Bearing System
,”
Commun. Nonlinear Sci. Numer. Simul.
,
15
(
9
), pp.
2659
2671
.10.1016/j.cnsns.2009.09.028
19.
Weaver
,
B.
,
Dimond
,
T.
,
Kaplan
,
J.
,
Untaroiu
,
A.
, and
Clarens
,
A.
,
2014
, “
Gas-Expanded Lubricant Performance and Effects on Rotor Stability in Turbomachinery
,”
ASME
Paper No. GT2014-26980. 10.1115/GT2014-26980
20.
He
,
M.
,
2003
, “
Thermoelastohydrodynamic Analysis of Fluid Film Journal Bearings
,” Ph.D. thesis,
University of Virginia
,
Charlottesville, VA
.
21.
He
,
M.
, and
Allaire
,
P.
,
2002
, “
Thermoelasto-Hydrodynamic Analysis of Journal Bearings With 2D Generalized Energy Equation
,”
6th IFToMM International Conference on Rotor Dynamics
,
Sydney, Australia, Sept. 30–Oct. 3
.
22.
He
,
M.
,
Allaire
,
P.
,
Barrett
,
L.
, and
Nicholas
,
J.
,
2002
, “
TEHD Modeling of Leading Edge Groove Tilting Pad Bearings
,”
6th IFToMM International Conference on Rotor Dynamics
,
Sydney, Australia, Sept. 30–Oct. 3
.
23.
Weaver
,
B.
,
Younan
,
A.
,
Dimond
,
T.
,
Wang
,
Z.
,
Allaire
,
P.
, and
Clarens
,
A.
,
2013
, “
Properties and Performance of Gas-Expanded Lubricants in Tilting Pad Journal Bearings
,”
Tribol. Trans.
,
56
(
4
), pp.
687
696
.10.1080/10402004.2013.779402
24.
Clarens
,
A.
,
Younan
,
A.
,
Wang
,
S.
, and
Allaire
,
P.
,
2010
, “
Feasibility of Gas-Expanded Lubricants for Increased Energy Efficiency in Tilting-Pad Journal Bearings
,”
ASME J. Tribol.
,
132
(
3
), p.
031802
.10.1115/1.4001648
25.
Ng
,
C.
, and
Pan
,
C.
,
1965
, “
A Linearized Turbulent Lubrication Theory
,”
ASME J. Fluids Eng.
,
87
(
3
), pp.
675
682
.10.1115/1.3650640
26.
Elrod
,
H.
, and
Ng
,
C.
,
1967
, “
A Theory for Turbulent Fluid Films and Its Application to Bearings
,”
ASME J. Tribol.
,
89
(
3
), pp.
346
362
.10.1115/1.3616989
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