MEEN
626 – Modern Lubrication Theory: FALL08
Instructor: Dr. Luis San Andrés, ENPH 118, Phones: 862
2-4744, LsanAndres@Mengr.tamu.edu
Class Time: T, R 8:00-9:15 am ENPH 204
Office hours: T, R: 9:45-10:45 a.m., or by appointment
Catalog Course Description: Development of Reynolds
Equation from Navier Stokes equations for study of hydrodynamic lubrication
theory as the basis for bearing design; applications to simple thrust and
journal bearings and pads of various geometries; hydrostatic lubrication,
floating ring bearings, compressible fluid (gas) lubrication, grease
lubrication, dynamically loaded bearings, half speed whirl and stability.
Prerequisites: MATH 308, MEEN 345 or equivalent.
MY
OBJECTIVES: To introduce the fundamental physical principles of the classical theory
of hydrodynamic lubrication and to review the latest advances and applications
to high speed, externally pressurized, turbulent flow bearings and seals with
process fluids. To provide guidance on the important aspects of modern
lubrication theory and novel applications. The class material emphasizes the
understanding of physical principles and the effects of fluid film bearings on
the dynamics of rotating machinery.
Text Book: San Andrés, L. Modern
Hydrodynamic Lubrication Theory, Class Notes (~350 pages) pdf files
(Notes 0-15) available at class web site http://phn.tamu.edu/me626
References: San
Andrés, L., Introduction to Pump Rotordynamics (26 p.), Hydrodynamic fluid film
bearings and their effect on the stability of rotating machinery (35 p.),
Annular pressure seals and hydrostatic bearings (36 p.) von Karman Institute - RTO Lecture Series, RTO-MP-AVT-143, DESIGN AND ANALYSIS OF
HIGH SPEED PUMPS,
Childs, D., Turbomachinery
Rotordynamics, J. Wiley Pubs., 1993, Chps. III & IV.
Szeri, A., Tribology: Friction, Lubrication & Wear,
Hamrock, B., Fundamentals of
Fluid Film Lubrication, McGraw-Hill, Inc., 1994.
Selected journal papers
(mandatory reading) listed in Index of
Notes (pages 7-ff Syllabus). Set # 2 (199 pages)
Course Outline: TWO 75 min. lectures/week. Group homework
assigned & graded. Two exams and a group selected project.
EXAMS: 1: Design of thrust and
journal bearings, Thursday, October 2, 8:00-9:15 p.m.
2: Rotordynamic and Bearings, Tuesday, November 20,
8:00-9:15 a.m..
GRADING: Group Assignments 20%
Weekly
(individual) quizzes 5%
First
Exam 25%
Second
Exam 25%
Class
Project 25%
(proposal due Thursday, November 6)
100%
All material enclosed is copyrighted by Dr. Luis San Andrés.
No distribution of the material listed below without express permission from
the author.
All documents are in ADOBE pdf format
(Acrobat Reader 7.0 needed), except those noted below as X(erox) copies.
Send all comments or questions to LsanAndres@Mengr.tamu.edu
Index To
Class Notes Fall 2008
click on hyper-link to download pdf files - LINKS TO MATHCAD PROGRAMS NOT ENABLED
Lecturer Reference (zipped file – 4 MB contains an expanded summary of most
material learned in course)
San Andrés, L., Introduction to Pump Rotordynamics (26 p.), Hydrodynamic fluid film bearings and their effect on the stability of rotating machinery (35 p.), Annular pressure seals and hydrostatic bearings (36 p.) von Karman Institute - RTO Lecture Series, RTO-MP-AVT-143, DESIGN AND ANALYSIS OF HIGH SPEED PUMPS
è Note below – items marked XX are latest updates (2007-08)
,
|
Notes |
Content |
|
i |
Introduction to Hydrodynamic
Lubrication (15 p) The
basic laws of friction. Fluid Film Bearings. Basic Operational Principles.
Hydrodynamic and Hydrostatic Bearing Configurations. Example of rotordynamic
study. Performance objectives. Appendix. Applications of Tribology in the 21st century (5 p) |
|
1 |
The fundamental
assumptions and equations of lubrication theory (8 p) The
fundamental assumption in Lubrication Theory. Derivation of thin film flow
equations from Navier-Stokes equations. Importance of fluid inertia effects
in thin film flows. Some fluid physical properties |
|
2 |
Classical Lubrication
Theory (10 p) Derivation
of Reynolds equation for laminar flow bearings. Boundary conditions and types
of liquid cavitation. Appendix: (16
p) One dimensional
slider bearing, Rayleigh (step) bearing and circular plate squeeze film
damper |
|
3 |
Kinematics of motion in
cylindrical journal bearings (10 p)
Reynolds
equation for cylindrical journal bearings. Kinematics of motion and film
thickness. Distinction between fixed and rotating coordinates. The pure
squeeze velocity vector. Examples of journal motion. MATHCAD
program for display of pressure field in short length journal bearings. |
|
4 |
Static load performance of
plain journal bearings (14 p)
The
long and short bearing models. Pressure field and fluid film forces on short
length journal bearings. Equilibrium condition, load capacity and the
Sommerfeld number. MATHCAD program
for calculation of equilibrium eccentricity in a short length journal
bearing. |
|
5 |
Dynamics of a
simple rotor-fluid film bearing system
(40 p) Equations
of motion of a rigid rotor. The concept of force coefficients. Derivation of
stiffness and damping coefficients for the short bearing. Stability analysis
and the effect of cross-coupled stiffness. Effect of rotor flexibility on
stability and imbalance response. Appendix Physical interpretation of dynamic
forces for circular centered whirl (14 p) MATHCAD
program for evaluation of force coefficients in short length bearings MATHCAD
program for prediction of threshold speed of instability and imbalance
response of a rigid rotor supported on laminar flow short length journal
bearings (no fluid inertia). MATHCAD
program for prediction of transient response of rigid rotor supported on
short length journal bearings or SFDS. |
|
6 |
Liquid cavitation in
fluid film bearings (18 p)
Appropriate
boundary conditions for a sound cavitation model. The basics of a universal
cavitation model (algorithm). Appendix
Dynamic cavitation in journal
bearings and squeeze film dampers (7
p) MATHCAD
program for calculation of pressure fields in 1-D bearing (Mass conservation
model and Reynolds condition). |
|
7 |
Finite length journal
bearings (14 p)
Evaluation
of dynamic force coefficients in finite length bearings using a perturbation
of the flow equations. Finite Element models: basic equations and their
solution. FORTRAN
program for prediction of static load and force coefficients in multiple pad
bearings (distribution limited). Appendix A
primer to tilting pad bearings (33
p) |
|
8 |
Turbulence in Fluid Film
Bearings (23 p)
The
nature of turbulence. Turbulence equations in thin film flows. Turbulence
flow models. The bulk-flow model of turbulence, Hirs’ and Moody’s friction factors. MATHCAD
program for prediction of turbulent friction factors. |
|
9 |
Fluid inertia and
turbulence in fluid film bearings (23 p)
When
fluid inertia effects are important. Bulk-flow model for inertial flows.
Turbulence and inertia in short length journal bearings and open end dampers. MATHCAD program for display of pressure fields (viscous + inertial) in
superlaminar flow bearings and SFDs. MATHCAD
program for prediction of threshold speed of instability and imbalance
response of a rigid rotor supported on turbulent flow short length journal
bearings (no fluid inertia). |
|
10 |
A thermohydrodynamic bulk-flow
model for fluid film bearings (25 p)
The
complete set of bulk-flow equations for the analysis of turbulent flow fluid
film bearings. Importance of thermal effects in process fluid applications. A
CFD method for solution of the bulk-flow equations. |
|
11 |
Floating ring oil
seals for compressors and Long (laminar
flow) oil seals (17p) MATHCAD
program for prediction of force coefficients in turbulent flow short length annular
pressure seals. |
|
12 |
Annular pressure (damper) seals and
hydrostatic bearings (36 p) The
mechanism of centering stiffness in seals. Force coefficients for
short-length pressure seals. Ddesign of annular seals: swirl brakes, impact
on rotordynamics. Hydrostatic bearings in modern applications. The principle
of hydrostatic lubrication. Effects of recess volume-fluid compressibility on
force coefficients for operation at low and high frequencies. Applications of
hydrostatic bearings MATHCAD
program for prediction of frequency dependent force coefficients in 1-D
hydrostatic bearings. |
|
13 |
Squeeze Film Dampers
(SFDs) (16
p) Appraisal
of the art. Design considerations. Force Coefficients. Lubricant cavitation
and air entrainment in SFDs. Response of a Rigid Rotor Supported on
open-ended SFDs. (*) Digital video clips showing air entrainment in a SFD available at http://phn.tamu.edu/TRIBGroup MATHCAD
program: prediction of imbalance response of rigid rotor supported on short
length SFDs with fluid inertia effects. |
|
14 |
Experimental identification of bearing force coefficients (19 p) includes paper on Instrumental Variable Filter method for bearing parameter identification. MATHCAD
program implementing impedance and IVF methods for identification of
parameters in a simple mechanical system. |
|
15 |
Note: 9
MegaBYTE document - DO NOT OPEN this document in the browser. RIGHT CLICK
mouse and select “SAVE TARGET AS …” to download file. (reading assignments) Pinkus,
O., 1987, “The Reynolds Centennial: A Brief History of the Theory of
Lubrication,” ASME Journal of Tribology,
Vol. 109, pp. 1-20. Szeri,
A., 1987, “Some Extensions of the Lubrication Theory of Osborne Reynolds,” ASME Journal of Tribology, Vol. 109,
pp. 21-36. Sun,
D.C., 1997, “Equations Used in Hydrodynamic Lubrication”, Lubrication
Engineering, January, pp. 18-25. San
Andrés, L., 1989, “Approximate Design of Statically Loaded Journal Bearings, ASME Journal of Tribology, Vol. 111,
pp. 391-393. Lund,
J.W., 1987, “Review of the Concept of Dynamic Coefficients for Fluid Film
Journal Bearings, ASME Journal of
Tribology, Vol. 109, pp. 37-41. Allaire,
P., and R.D. Flack, 1981, “Design of Journal Bearings for Rotating
Machinery,” Proceedings of the 10th Turbomachinery Symposium, pp.
25-45. Heshmat,
H., 1991, “The Mechanism of Cavitation in Hydrodynamic Lubrication,” STLE Tribology Transactions, Vol.
34, pp. 177-186. Klitt,
P., and J.W. Lund, 1986, “Calculation of the Dynamic Coefficients of a
Journal Bearing Using a Variational Approach,” ASME Journal of Tribology, Vol. 108, pp. 421-425. |
|
15 |
(reading assignments)) Hirs,
G.G., 1973, “A Bulk-Flow Theory for Turbulence in Lubricant Films,” ASME Journal of Lubrication Technology,
pp. 137-146. Hashimoto,
S., S. Wada, and M. Sumitomo, 1988, “The Effects of Fluid Inertia Forces on
the Dynamic Behavior of Short Journal Bearings in Superlaminar Regime,” ASME Journal of Tribology, Vol. 110,
pp. 539-547. “Is the Writing on the Wall for Oil Lubricated
Bearings in Pumps,” 1995, World Pumps, December, pp. 38-41. Pinkus, O., 1984/5, “Anisothermal Fluid Films in
Tribology,” San Andrés, L., 1990, “Turbulent Hybrid Bearings
With Fluid Inertia Effects,” ASME
Journal of Tribology, Vol. 112, pp. 699-707. Launder, B.E., and M. Leschziner, 1978, “Flow in Finite-Width,
Thrust Bearings Including Fluid Inertia Effects,” ASME Journal of Lubrication Technology, Vol. 100, pp. 330-338. Zeidan, F., L. San Andrés, and J.M. Vance, 1996,
“Design and Application of Squeeze Film Dampers in Rotating Machinery,”
Proceedings of the 25th Turbomachinery Symposium, pp. 169-188. Childs,
D.W. and Vance, J.M., “Annular Gas Seals and Rotordynamics of Compressors and
Turbines,” Proceedings of the 26th
Turbomachinery Symposium, pp. 201–220, September 1997. Diaz, S., and L. San Andrés, "A Method for
Identification of Bearing Force Coefficients and its Application to a Squeeze
Film Damper with a Bubbly Lubricant,” STLE Tribology Transactions, Vol. 42,
4, pp. 739-746, 1999. |
|
16 |
Other References with Useful Information (paper copy only, ask your course instructor) Tribological
Design Data Guide, Part 1: Bearings, 1995, The Institution of Mechanical Engineers,
Tribology Group, Tribological
Design Data Guide, Part 2: Lubrication, 1995, The Institution of Mechanical Engineers,
Tribology Group, Zeidan, F., and B. Herbage, 1991, “Fluid Film
Bearing Fundamentals and Failure,” Proceedings of the 20th
Turbomachinery Symposium, pp. 161-186. |
Recommended
Tribology Journals
Journal of Tribology (Transactions of the ASME).
Published quarterly by the American Society of Mechanical Engineers,
Tribology Transactions (Journal of the Society of Tribologists and
Lubrication Engineers). Published quarterly by STLE,
Lubrication Engineering (STLE magazine). Published
monthly by STLE,
Wear, Five volumes per year, edited by Prof D.Dowson.
Published by Elsevier Science B.V. Sequoia SA,
Tribology International. Published bimonthly by
Butterworth Heinemann,
Journal of Engineering Tribology (Proceedings of the
Institution of Mechanical Engineers, Part J). Published quarterly by Mechanical
Engineering Publications Ltd.
Recommended
reference books