stiffness & damping coefficients of journal & thrust bearing

[2126]

i'm going to make a rotordynamic modelling using mat-lab software package,to identify the dynamic behaviour of the rotor under various rotating speed and excitation forces, actually it is a steam turbine rotor with multibearing system, i have a barrier in finishing my task, that is i don't know the values of the bearing's dynamics coefficients (stiffness and damping coefficients) ,do anyone know the calculation methods to determine these values or where to find these data if they are already available, for your information, the bearing type are hydrodynamic tilting pad bearing, elliptical (lemon bore) bearing,and tilting pad thrust bearing

 

[vanstoja]

See my reply to your other 11/28/03 query on tilting pad radial bearing stiffness and damping coefficients.
For tilting pad thrust bearings and 2,3,4-lobed radial bearing stiffness and damping coefficients, there is probably less published data in the open literature and an extensive literature search might be needed to uncover the best current data. Possibly, the best sources of such data are the UVirginia/ROMAC consortium publications on bearings, rotordynamics and centrifugal pump wear ring seals, many of which have been summarized in the open literature. Another possible source of such data are the reports of the NASA/Lewis Lab (Cleveland) on stabilized fluid-film bearings.

 

[vanstoja]

A recent paper giving references to elliptical (2-lobe) bearing dynamic coefficients is:
Hashimoto,H. & Matsumoto,K.(2001), "Improvement of Operating Characteristics of High Speed Hydrodynamic Journal Bearings by Optimum Designart I-Formulation of Methodology and Its Application to Elliptical Bearing Design", Trans.ASME/J.of Tribology, Vol.123, No.2, Apr. 2001. Among the 21 references, the papers by Glinecke,etal (1980), Tribol. Int. Vol.15, No.6, pp.297-309 and Hashimoto (1992, STLE Tribol. Trans. Vol.35, No.4, pp.619-626 both deal with elliptical bearing dynamic coefficients.
Other recent papers dealing with calculation or testing of fluid film bearing dynamic coefficient operating variables are found in:
ASME Trans./J.Tribology V122, No.2, Apr.2000, pp.616-621 and V121, No.3, July 1999, pp.499-505 and pp.517-522. The last addresses 5-pad tilting pad journal bearings.

 

[vanstoja]

An AOL/Google search for "bearing dynamic coefficients" brought up several sites with papers on the subject, other reference sources and the UVirginia/ROMAC listing of computer programs updated through 6/29/01. A paper by Don Bently cites the following book as a possible source of compiled bearing dynamic coefficients:
Tsuneo Someya, Journal Bearing Databook, Springer-Verlag, 1989
A listing of 38 references by UVA authors on experimental bearing work is found at

http://www.virginia.edu/faculty/UVA.Bearings.Review.pdf

ROMAC computer programs are found at

http://www.virginia.edu/romac/software/info.htm

 

[unclesyd]

Here is a outfit that does it all pertaining to rotary equipment. We used them and some others using their software on some high speed equipment. I wasn't directly involved but I know the engineers that were involved were quite satisfied.

http://www.rsr.com/index.html