Tribology Group

Rotordynamics Laboratory
Turbomachinery Laboratory – Texas A&M University

Contact Information: Lsanandres@mengr.tamu.edu

Phone: (979) 862 4744, (979) 845 0160   Fax: (979) 845 6382

The Tribology Group/Rotordynamics Laboratory is one of the most active and well equipped research groups in the Turbomachinery Program at Texas A&M University. The laboratory area totals 1600 square feet in two test cells at the Turbomachinery Laboratory.

In the field of Tribology (friction, lubrication and wear) research focuses on  experimentally verified computational film flow models for the prediction of the static and dynamic force response of fluid film bearings; in particular hydrostatic bearings, tilting pad bearings, annular pressure seals, squeeze film dampers, floating ring bearings, and gas damper bearings and seals.

In the Rotordynamics field, research deals with the measurement and prediction of the dynamic lateral vibration characteristics of turbomachinery, encompassing both the traditional aspects of rotordynamics analysis and investigations into the fluid film-structure interaction forces that influence rotordynamics, with a major emphasis in fluid film dampers and gas bearings.

GOALS

*      To provide an advanced education in the fields of fluid film lubrication and rotordynamics
Our goal is to provide both graduate and undergraduate students with an in-depth education on the fundamental aspects of fluid film bearing technology and dynamics of high speed rotating machinery. Our current research covers a wide spectrum of novel bearing and seal applications and rotordynamics addressing to current and future industrial needs

*      To develop advanced analytical and computational tools for the analysis and design of process fluid film bearings
The trends in turbomachinery demand the largest output power to weight ratios and require flexible mechanical rotating components able to operate at increased speeds, temperatures and pressure differentials. Best efficiency and compactness can only be achieved with the effective use of the process liquid or gas as the lubricant in the support bearings

*       To procure experimental measurements of the static and dynamic force performance of fluid film bearings and squeeze film dampers for industrial applications
Our experimental research program on squeeze film dampers has an outstanding international reputation. Major advances have resulted from the analysis and experimental verification of the forced performance of squeeze film dampers due to the effects of feeding grooves, fluid inertia and dynamic lubricant cavitation. The latest experimental measurements provide fundamental understanding on the complex flow mechanics of air ingestion and entrapment (bubbly lubricant mixtures) in the dynamic performance of squeeze film dampers

*       To advance technologies for Oil-Free turbomachinery and micro-turbomachinery
Current research focuses on the analysis and experimental verification of the static and dynamic forced performance of gas bearings and seals for applications in micro-turbomachinery (40 Kw-500 kW) and portable power hybrid systems (SFOC & gas turbines).

 

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Annual Progress Reports

Download short reports describing major achievements, publications and funding

2002  2003  2004 

2005  2006  2007(pdf format)
2008


Slide shows for TRC funded projects (May 08)      
NEW

Tech Report

Title

 

Group Progress report

TRC-SFD-1-08

Dynamic Performance of a Squeeze Film Damper with Non-Circular Motions: Multi-Frequency Excitations Reproducing Multi-Spool Engine Operating Conditions

TRC-Seal-1-08

A Novel FE Lubrication Model for Improved Predictions of Force Coefficients in Off-Centered Grooved Oil Seals

TRC-B&C-1-08

Dynamic Forced Response of a Rotor-Hybrid Gas Bearing System due to Intermittent Shocks

TRC-B&C-2-08

TRC-B&C-3-08

Thermohydrodynamic Analysis of Bump Type Gas Foil Bearings: Model and Predictions & Rotordynamic Measurements on a High Temperature Rotor Supported on Gas Foil Bearings

TRC-B&C-5-08

Development of a Test Rig for Metal Mesh Foil Gas Bearing and Measurements of Structural Stiffness and Damping in a Metal Mesh Bearing

TRC-B&C-4-08

The Effect of (Nonlinear) Pivot Stiffness on Tilting Pad Bearing Dynamic Force Coefficients

TRC presentation

Simplified Thermohydrodynamic Analysis of (rigid geometry) Journal Bearings

 

Slide show: ISCORMA -2008 Plenary Lecture on Gas bearings at TAMU

 

Current Projects  2006-2008

 

·         Research Experiences for Undergraduates: Development of Microturbomachinery

Sponsor: National Science Foundation (3 years) 2006-2009, REU#0552885

P.I: Dr. Wayne Hung (ENTC), co-pi: Dr. Luis San Andrés

Objective: The REU Summer Program funds  30 junior-level students to conduct hand-on training and research in mechanical, manufacturing, industrial, or materials engineering topics related to technological advances in microturbomachinery. This program is part of a larger scale multidisciplinary research project at TAMU to develop microturbines to enhance defense, homeland security, transportation, and aerospace applications. Activities include a series of informative seminars, field trips and social events to complement the research activities while enhancing the group cohesiveness. Students will also sharpen their communication skills through the writing of a research report and presenting their research work to industry (TRC).

 

Excellent facilities and services, small size research teams, exciting interdisciplinary topics, and staying in the intellectual city of College Station provide students an invaluable research experience when participate in this cutting edge technology development.
    
Download posters prepared by UG-REU students, Summer 2007

Gas Foil Bearings (Alex Martinez)

Turbochargers (Adam Wilson)

Gas Tilting Pad Bearings (H. Suh)

·         Nonlinear Rotordynamics of Automotive Turbochargers: Computational Analysis of Floating Ring Journal Bearings (FRBs) and Experimental Validation in a Turbocharger Test Rig

Sponsor: Honeywell Turbo Technologies 2001-2008

Objective: To advance (experimentally validated) computational tools for prediction of the dynamic forced response of turbocharger rotors supported on FRBs.

Status: Virtual Laboratory (computational software) is a production tool at Honeywell. Research continues to model compressor and turbine aerodynamic forces and more complex bearing geometries. Advice on foundation model to Jiatong University (China).

 

·         Gas Bearings for Oil-Free Turbomachinery

Sponsor: TRC 2000-2008

Objective: To advance the technology of inexpensive reliable gas bearings for micro gas turbines and micro power systems

Status: Further measurements for load on pad and load between pad conditions and correlation to computational model predictions successful. Demonstrated controlled pressurization avoids excitation of critical speeds with smooth operation over extended speed zones. Computational program and GUI available to TRC members.

 

·         Foil Gas Bearings for Oil-Free Turbomachinery

Sponsors: National Science Foundation (2003-2007), TRC  (2004-2008), NASA Glenn RC (2007-2009),

Objective: To quantify the physical parameters of bump foil gas bearings for micro turbine applications

Status: Extensions to computational analysis include models for the top foil (1D and 2D). Code and GUI available to TRC members. Codes have unsurpassed speed of execution since foil structure is modeled prior to integration with gas film analysis. Test rig modified with AC motor running to 50 krpm and with centrifugal clutch and DC motor for start up. Tests for structural parameter identification conducted at high temperatures (250 F) using a heater.

 

·         Hybrid Brush Seals for Gas Turbines

Sponsor: Siemens Power Generation  2006-2008. Hardware from Advanced Turbomachinery Solutions (ATS)

Objective: Measure leakage versus pressure for increasing shaft speeds, identify mechanical parameters from improved shoed brush seal and advance computational models for prediction of the dynamic forced performance of shoed brush seals.

Status: Test rig for identification of stiffness and damping coefficients revamped for tests at high temperature (300C). Shaker load tests at various frequencies will be conducted to identify the stiffness and equivalent damping coefficients of shoed brush seal. Leakage vs. supply pressure tests completed.

 

·         Dynamic Force Performance of Sealed Squeeze Film Dampers

Sponsor: TRC 2004-2008

Objective: To assess effect of mechanical end seal on dynamic forced performance of a test SFD.

Status: Test rig accommodates a SFD with a (nonrotating) mechanical seal that adds dry friction to system while containing lubricant for extended periods of time and without side leakage. Seal design most successful to avoid air ingestion and entrapment. Structural, dry-friction parameter of mechanical seal and squeeze film damper damping and inertia coefficients identified from single frequency load tests forcing unidirectional and circular centered orbits. Predicted SFD force coefficients agree well with measured ones.

 

·         TRC Update of computational software

Sponsor: TRC  2007

Objectives: Update fluid film bearing predictive software by accounting for thermal effects in radial bearings and pivot stiffness effects in tilting pad journal bearings.

 

·         CLIN 004 - Tool/Method Development of the AFRL Upper Stage Technology Program (USET) Turbopump USET Development

Sponsor: Northrop Grumman  2005-2008

Objective: Experimental validation and enhancements of computational models for prediction of dynamic forced performance of cryogenic liquid hydrostatic bearings - USAF Upper Stage Engine Technology Program. 

(a): To develop hydrostatic bearing tool with capability for modeling the non-linear forced response of fluid film bearing, i.e. bearing reaction forces (impedance models) as a function of instantaneous journal position, velocity and acceleration

(b): Create capability for modeling speed dependent non-linear operation in mixed flow regime (fluid and solid contact), including prediction of lift-off speed

(c): Experimental Study of Hydrostatic / Hydrodynamic Thrust Bearings: 25 krpm, 250 psi, 600 lbf, water bearings.

 

 Personal interest:

·         On Site Identification of Bearing Parameters in Flexible Rotor Systems

To develop procedures for practical on site reliable bearing parameter identification techniques

SPONSOR: none

 

 

 

 

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Dr. Luis San Andrés, Professor & Group Leader
ASME Fellow, STLE Fellow, Mast-Childs Tribology Professorship
Dr. San Andrés has an international reputation as a qualified analyst and experimentalist in the fields of fluid film lubrication and rotordynamics. Dr. San Andrés has managed research projects with a total value exceeding 5.5 million dollars. He directs a laboratory with an average of seven fully supported research assistants per year. Dr. San Andrés has educated many graduate students currently practicing their skills and providing services and leadership to turbomachinery manufacturers. Dr. San Andrés and his students have published extensively in the archival literature: 110 peer reviewed papers, 50+ invited conference papers, 100+ technical reports. Dr. San Andrés also holds five patents and the copyright for the hydrostatic and gas film family of computer programs for liquid & gas film bearing analysis and design.

Dr. San Andrés has provided major advances to the technology of hybrid bearings (hydrostatic / hydrodynamic) for applications in primary power space turbopumps. The bearings investigated, both theoretically and experimentally, include flexure-pivot tilting pad bearings, angled injection hybrid bearings and foil-bearings. Current research interests include analysis of hybrid thrust bearings and two-phase fluid seals for cryogenic applications, and high speed gas face seals and bearings with enhanced damping characteristics.

The Tribology Group has developed advanced and efficient computational models for the analysis and design of process-fluid film bearings (hydrostatic and hydrodynamic), gas bearings including foil bearings, gas damper and labyrinth seals, tilting pad bearings and squeeze film dampers. The thermo hydrodynamic flow models account for fluid inertia and variable properties, flow turbulence in exotic bearing geometries. Applications to high-speed turbomachinery include cryogenic turbopumps, aircraft jet engines, industrial compressors, etc. Users include Boeing-Rocketdyne, Pratt & Whitney, NASA Research Centers and Contractors, Philips Laboratory - USAF, TAMU Turbomachinery Research Consortium members, Sulzer-Bingham, GE Aircraft Engines Group, SNECMA-SEP-France, Hamilton Std., and educational institutions like MIT and Cleveland State University.

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Distinctions – Former Students

Name

Society

Distinction

Contribution

Deborah Osborne- Wilde

ASME Tribology Division

2004 Marshal Peterson Young Investigator Award

Gas Bearings and Seals

Sergio Diaz

ASME Tribology Division

2003 Burt Newkirk Investigator Award 

Squeeze Film Dampers

Nicole Zirkelback

Texas A&M University

1998 Outstanding Graduate Student Award

Gas Annular and Face Seals

  Several graduate and undergraduate students have obtained STLE scholarships and fellowships

 

2004 BEST Rotordynamics Paper Award – IGTI  Structures and Dynamics Committee)

Rubio, D., and L., San Andrés, 2004, “Bump-Type Foil Bearing Structural Stiffness: Experiments and Predictions”, ASME Paper GT 2005-53611 (accepted for publication at ASME Journal of Gas Turbines and Power)

2003 Best Rotordynamics Paper Award (IGTI, Structures & Dynamics Committee)

Wilde, D.A., and San Andrés, L., 2003, “Experimental Response of Simple Gas Hybrid Bearings for Oil-Free Turbomachinery,” ASME Paper GT 2003-38833, ASME Turbo-Expo 2003 Conference, Atlanta, GA, June (accepted for publication at ASME Journal of Gas Turbines and Power).

 

 

Favorite Links

*      Turbomachinery Laboratory     

*      Turbomachinery Research Consortium

*      XLrotor    a commercial rotordynamics/bearing analysis package

*      rotordynamics.org, a gateway to a collection of technical literature on rotordynamics.

 

Personal Interests

*      Roca Azul, the premier Latin Rock & Blues Band in the Brazos Valley

*      PHN, Professional Hispanic Network at TAMU

 

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Last revised: June 10, 2008