Turbomachinery Laboratory at Hanyang University. Rotordynamics. Bearings. Seals. Dampers.

Hanyang University Department of Mechanical Engineering

Last revised: Mar. 26, 2024

MEE3048 Rotating Machinery Diagnostics and Vibration Analysis

1. Class information
• Class Year and semester: 2024, SPRING semester
• Course No. : MEE3048
• Course title: Rotating Machinery Diagnostics and Vibration Analysis
• Credit-Lecture Hour-Practice Training: 3.00-3.00-0.00
• Course outline: One Three-hour lecture/week
• Organizing Department: Mechanical Design Engineering (Graduate School; Seoul)

2. Instructor information
• Name: Dr. Keun Ryu
• Department: Mechanical Design Engineering
• Email: kryu@hanyang.ac.kr
• Web: http://turbolab.hanyang.ac.kr/MEE3048.html

• Office hours: By scheduled appointment (E-mail in advance required)
• About office hours: This is to encourage individual interaction between the students and the instructor. Students should prepare by organizing questions in advance.

3. Course objective
To provide guidance on the important aspects of modern rotating machinery diagnostics and vibration measurement theory, as well as thier novel applications. The class material emphasizes the understanding of physical principles on the dynamics of rotating machinery.

4. Course Description:
The class will review basic vibration theory and how it is used to diagnose and solve machinery vibration problems, followed by a brief introduction to dynamics of rotating machinery. The objectives of vibration measurements in rotating machinery, how they affect the choice of instrumentation, basic instrumentation systems and transducers will be discussed. In addition, tethods for parameter identification (stiffness, damping, and mass) from vibration measurements will be described. The use of spectrum analyzers, signal filters, and special analyzers for rotating equipment will be described. Most importantly, machinery problem diagnostics using the vibration signal will be described.

* Note that this class follows the IC-PBL+ format.

The IC-PBL+ is an "industry-linked, problem-based, project course method" focused on the development of various capabilities required for future leaders of society. As an advanced program of the IC-PBL, the program has been designed to provide students with a graduate-level educational experience to foster "scholars" with initiative, "co-workers" who are capable of performing industry-based research with interdisciplinary thinking, and international "leading researchers" with global researching capabilities.
　

5. References: ALL Available in Hanyang University Library
- Fundamentals of Rotating Machinery Diagnostics, Donald Bently, Publisher: American Society of Mechanical Engineers, Published: 01/29/2003, ISBN13: 978-0971408104, ISBN10: 0971408106
- Rotating Machinery Vibration: From Analysis to Troubleshooting, Second Edition, Maurice L. Adams, Publisher: CRC Press, Publication Date: December 23, 2009, ISBN-10: 1439807175, ISBN-13: 978-1439807170
- Rotordynamics, J.S. Rao, Publisher: John Wiley & Sons Inc, ISBN-10: 0470274484, ISBN-13: 978-0470274484
- Machinery Vibration and Rotordynamics, John M. Vance, Fouad Y. Zeidan, Brian Murphy, Wiley, 2010, ISBN-10: 0471462136, ISBN-13: 978-0471462132
- Turbomachinery Rotordynamics with Case Studies, D. Childs, Minter Spring, 2013, ISBN-10: 0615852726, ISBN-13: 978-0615852720

- Modern Lubrication Theory, L. San Andres, Texas A&M University Digital Library, 2010

- API Recommended Practice 684

- Selected Technical papers: SEE Reading assignments below

6. Grading
IC-PBL+ activity 65%(=Weekly presentation 35% + Final report 20% + Final presentation 10%)*, Mid-term exam (15%), Final Exam (15%), Attendance (5%)
* Weekly presentation 35%: Group 20% + Individual 15%

Final report 20%: Group 10% + Individual 10%

Final presentation 10%: Group 5% + Individual 5%

** Template for weekly task plan: Your group presentation must include the contents in this report.

℃ Before each weekly presentation, please turn in your team work (both weekly task plan and the PowerPoint) to Dr. Ryu.

7. Lecture material and topics

• Week 1
Introduction to Rotordynamics

• Week 2
Introduction to Vibration Measurements

Characteristics of the Vibration Signal in Rotating Machinery

• Week 3

1) Notice: Quiz for fundamentals (Weeks 5 & 6)
Study the following chapters in the book titled "Mechanical Vibrations, 5th Edition" written by S. S. Rao (2011, Prentice Hall, ISBN 978-0-13-212819-3)

https://www.researchgate.net/profile/V-T-T-Nguyen/publication/273330566_Basic_Mechanical_Vibrations/links/54fecf170cf2741b69f164f2/Basic-Mechanical-Vibrations.pdf

Chap. 2.4 Response of First-Order Systems and Time Constant
Chap. 2.6 Free Vibration with Viscous Damping (Only from 2.6.1 Equation of Motion to 2.6.4 Energy Dissipated in Viscous Damping)
Chap. 2.9 Free Vibration with Coulomb Damping (Only from 2.9.1 Equation of Motion to 2.9.2 Solution)
Chap. 2.10 Free Vibration with Hysteretic Damping
Hint: Please read "REVIEW QUESTIONS" ℃ Week 5

Chap. 3.3 Response of an Undamped System Under Harmonic Force
Chap. 3.5 Response of a Damped System Under F(t)=F0e^(it)
Chap. 3.6 Response of a Damped System Under the Harmonic Motion of the Base
Chap. 3.7 Response of a Damped System Under Rotating Unbalance
Chap. 3.8 Forced Vibration with Coulomb Damping
Chap. 3.9 Forced Vibration with Hysteresis Damping
Hint: Please read "REVIEW QUESTIONS" ℃ Week 6

2) Group Assignment 1

https://dyrobes.com/paper/understanding-amplitude-and-phase-in-rotating-machinery/

https://dyrobes.com/paper/introduction-to-rotor-dynamics-critical-speed-and-unbalance-response-analysis/

https://dyrobes.com/paper/rotor-bearing-stability/ (Tentative)

Each group will have 30 minutes for presentation.
Please make a summary of the paper which your group studies using powerpoint format.
1) # of Slides: No more than 40 pages
2) Due: Week 4
3) Contents: Summary, What you learn, What you still do not understand, What you want to learn more, References

•Week 4

1) Group assignment 1: Presentation (Email the slides to Prof. Keun Ryu)

2) Data acquisition systems

- Basics of DAQ systems: Ez-TOMAS

- Instrumentation for rotordynamic test rig

- Important reading

http://turbolab.hanyang.ac.kr/Rotor%20Dynamics%20Measurement%20Techniques.pdf

http://turbolab.hanyang.ac.kr/Effective%20Machinery%20Measurements%20using%20Dynamic%20Signal%20Analyzers%20(Application%20Note%20243-1).pdf

http://turbolab.hanyang.ac.kr/The%20Fundamentals%20of%20Signal%20Analysis%20(Application%20Note%20243).pdf

3) Phase: Why phase information is important for diagnosing machinery problems

4) Group work (Experiments): Experimental modal analysis

https://rotorlab.tamu.edu/me459/H2%20STA%20459%20Free-free%20modal%20analysis.pdf

https://rotorlab.tamu.edu/me459/README%20for%20homework%202.zip

5) Instrumentation (Proximity Probes, Accelerometers, Velocity Transducers, Signal Conditioning, Display, and Storage)
　

Displacement sensors: Eddy current sensors

- https://dam.bakerhughesds.com/m/8164bf26bda9534/original/3300-XL-50mm-Proximity-Transducer-System-Datasheet-174014-pdf.pdf

- https://www.bakerhughesds.com/sites/g/files/cozyhq596/files/2019-06/3300%20XL%20NSv%20Proximity%20Transducer%20System%20Datasheet%20-%20147385.pdf

- Probe installation tips

Capacitive sensors: https://youtu.be/NC5bNjbdBMA

- Comparing Capacitive and Eddy-Current Sensors

- https://youtu.be/CGnQHmBzCSI

Fiber optic sensors: http://philtec.com/

- https://youtu.be/Lz3gbHqIkXk (Important)

- https://youtu.be/KX6pQN6kQFo (Important)

-https://youtu.be/S-5M4naxjtY

Accelerometers

- Basics on vibration shock & acoustic emission measurement. Learn more on acceleration measurement principles and technologies: https://youtu.be/ZqyykNHHe1s

- Specifications and datasheets. Detailed information on sensitivity, resonance frequency and other important specs: https://youtu.be/D5-dxhnifDg

- Mounting considerations. Get to know the seven different mounting methods for accelerometers: https://youtu.be/ncTBo6K7SWQ

- Potential damages & trouble shooting. How to avoid damage and tips & tricks for the daily use of accelerometers: https://youtu.be/BT0XuLlGUok

Force sensors

- Piezo vs. Strain Gauge. When to use which technology? A direct comparison of piezoelectric and strain gauge force sensors: https://youtu.be/hPalJ_0dFck

- Specifications of Piezoelectric 1-Component Force Sensors. Get to know the basics as well as the most important specifications of piezoelectric 1-comp. force sensors: https://youtu.be/cHZcKCRYtNM

Pressure sensors

- Introducing Piezoelectric Pressure Sensors. Piezoelectric pressure sensors are the preferred solution to measure dynamic pressures and pressure pulsations: https://youtu.be/70cc210ui_o

• Week 5

1) Quiz 1

2) Slow roll vectors: SLOW SPEED VIBRATION SIGNAL ANALYSIS

3) Orbit plots: What are Orbit plots

• Week 6

1) Quiz 2

2) Average shaft centerline

- The importance of monitoring shaft center line data

- Determining shaft centerline position in four easy steps

- Shaft centerline radial position

3) Bode plots

4) Rub and looseness

• Week 7

Signal processing

- Sampling waveforms and computing spectra

- https://www.etssolution-asia.com/s/Digital-Signal-Processing-Knowledge-Booklet.pdf

- Signal Processing: Why and how to apply filters
Filters are essential for sorting out undesired or disturbing effects: https://youtu.be/czF8k9b3H-4

• Week 8

Mid-term exam

• Week 9

Rotordynamic Instability, Subsynchronous vibration

- Myth: The End is Near ˇ I Have Rotordynamic Cross-Coupled Forces

• Week 10

Bearings, Seals, and Their Rotordynamic Effects

• Week 11

Anisotropic Bearing Stiffness.

• Week 12

Parameter Identification for Rotating Machinery. Synchronous Amplification Factor (SAF) and Damping Ratios

• Week 13

Transfer Functions (Impedance and Mobility Modeling)

• Week 14

Frequency Spectrum Analysis

• Week 15

Half and full spectrum plots

• Week 16

Final Exam

• Mid-term Projects (before 2018)

Please read the papers below very carefully!

- Design and Application of Squeeze Film Dampers in Rotating Machinery (F. Y. Zeidan, L. San Andres, and J. M. Vance)

- Application of High Speed and high performance fluid film bearings in rotating machinery (F. Y. Zeidan and D. J. Paquette)

- Annular Gas Seals and Rotordynamics of Compressors and Turbines (D. W. Childs and J. M. Vance)

• Review for mid-term and final exams (before 2018)

         - Rotordynamic issues in high speed turbomachinery ****
         - Hydrodynamic or Self-acting fluid film bearings vs Hydrostatic or externally pressurized fluid film bearings
         - Bearings to improve stability *
         - Squeeze film dampers
         - Radial fluid seals (annular, labyrinth or honeycomb)
         - Jeffcott- Föppl Rotordynamic Model ****
         - Synchronous and nonsynchronous whirl **
         - Slow roll vector compensation **
         - Why is “Phase” (timing) important? ****
         - Identification of heavy spot
         - How to validate linearity of rotor-bearing system ***
         - Crosstalk; Heavy spot; High spot; Whip & Whirl; Bearing attitude angle & Eccentricity & Eccentricity ratio ****
         - Synchronous Amplification Factor (SAF) ****
         - Bearing Anisotropic Stiffness: Typical Split Critical Speeds & Reverse whirl orbit **
         - Non Contact Displacement Probes (Eddy Current Proximity Probe)
         - Phase Measurement ****
         - Orbit plots
         - How to measure a deflection shape of rotor
         - Half spectrum vs Full spectrum **
         - Limitations of Spectrum Plots
         - Dynamics of rigid rotor-fluid film bearing systems ****
         - Sources of rotordynamic Instability & Subsynchronous vibration ****