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Risorse bibliografiche
Risorsa bibliografica obbligatoria
Risorsa bibliografica facoltativa
Scheda Riassuntiva
Anno Accademico 2018/2019
Scuola Scuola di Ingegneria Industriale e dell'Informazione
Insegnamento 097552 - ROTOR DYNAMICS AND DIAGNOSTIC B
Docente Pennacchi Paolo Emilio Lino Maria
Cfu 6.00 Tipo insegnamento Monodisciplinare

Corso di Studi Codice Piano di Studio preventivamente approvato Da (compreso) A (escluso) Insegnamento
Ing Ind - Inf (Mag.)(ord. 270) - BV (477) ENERGY ENGINEERING - INGEGNERIA ENERGETICA*AZZZZ097389 - ROTOR DYNAMICS AND DIAGNOSTIC A
Ing Ind - Inf (Mag.)(ord. 270) - BV (483) MECHANICAL ENGINEERING - INGEGNERIA MECCANICA*AZZZZ097552 - ROTOR DYNAMICS AND DIAGNOSTIC B

Obiettivi dell'insegnamento

This course aims at introducing the main concepts related of rotor dynamics and diagnostics.

 

Rotor dynamics is the key for the design and operation of many machines: turbine of any kind used for power generation, aircraft engines, electrical motors, centrifugal compressors, etc. Thus, the dynamics of the complete machine and of its main components, like shafts, bearings, seals and blades is presented in detail. Several design tools and examples are introduced.

 

Diagnostics is an emerging requirement in modern mechanical systems in order to shorten out-of-service and reduce operation costs. Very often, the faults are affecting the same components analysed by rotor dynamics and this makes the two parts of the course strictly connected. State-of-the-art techniques, based on both system model and data analysis, are introduced.

 

All the topics are analysed under practical and theoretical points of view, with several examples of application in real machines, of design cases and of case histories. The seminars, conducted by industry experts, are essential parts of the course.

 

More in detail, the aims of the course are:

  • To provide tools and methods to define the mathematical model of a rotor system, by considering its main sub-components
  • To provide the basics for the mechanical analysis of rotating machinery
  • To provide tools and methods to perform diagnostics of mechanical systems, by considering their main sub-components
  • To provide the basics for fault and damage diagnostics in mechanical systems
  • To provide the morphological description of the main sub-components of rotor systems

Risultati di apprendimento attesi

Knowledge and understanding

After passing the exam, the student:

  • knows the methodologies and the principles to describe in mathematical terms a rotor system and its main sub-components;
  • understands and knows how a rotor system is composed;
  • knows the basic aspects of diagnostics of mechanical systems;
  • knows the methodologies to perform diagnostics of some components of mechanical systems;
  • learns the methods of modeling rots systems;

 

Ability to apply knowledge and understanding

After passing the exam, the student:

  • is able to perform the modeling of rotor systems;
  • is able to understand and describe the functioning of a rotor system;
  • can calculate the dynamic response of a rotor system;
  • is able to address and analyze basic problems of diagnostics in a mechanical system;
  • can effectively communicate the results of the analysis performed on the dynamics of a rotor system;
  • can effectively communicate the results of the diagnostics of a mechanical system.

Argomenti trattati

Rotor dynamics

  • Finite beam models for lateral and torsional vibrations. Supporting structure modelling. Review of design standards (API, ISO). Flexible rotors balancing
  • Critical speeds, Campbell diagram, System response to common linear (unbalance, bow, misalignment, cracks) and non linear (rub, magnetic fields) excitations
  • Stability (effects of fluid film bearings, of steam flow, of magnetic bearings/fields)

Fluid-film bearings

  • Hydrodynamic lubrication, computational hydrodynamics, Geometry of fluid film bearings
  • Bearing design (static and dynamic characteristics), Journal bearing testing, Thrust bearing testing, Bearing coating materials, Bearing damages
  • Effects of electrical pitting

Seals

  • Geometry, modelling (bulk-flow, and CFD), dynamic characteristics calculation

Blade dynamics

  • Excitation causes
  • Design, HCF, Correction, LCF, Correction
  • Damping, snubbing, friction, vibration measurements

Diagnostics

  • Maintanance policies, condition monitoring, setting of alarms and trips, review of current standards
  • Model based approach (inverse dynamic problem), with case history analysis (steam, gas and hydro turbines)
  • Data driven approach (advanced signal analysis: time-frequency transformations, 2nd order cyclostationarity, envelope analysis, spectral kurtosis), with case histories (turbine gearbosx, train traction systems, engine firing)

Special topics

  • Wind turbine diagnostics
  • Roller element bearings diagnostics
  • Gear diagnostics

Seminars (speakers from industry)

  1. Industrial steam turbine design and operational requirements
  2. Rolling element bearing diagnostics

Prerequisiti

A good knowledge of calculus is required, especially regarding linear differential equations, matrix algebra and partial differential equations. The knowledge of finite element approach is suggested, but not mandatory. Similarly, the knowledge of basics of fluid mechanics and of signal processing is useful.


Modalità di valutazione

Organization of the course and methods of verification

The course is divided into a series of lessons and practical exercises, related to the topics of the lessons, aimed at consolidating the knowledge and methods learnt during the lessons.

The exam consists of an oral exam.

The oral exam consists in answering questions, in open form, that focus on all the topics covered in the course, accompanying the answering with equations, graphs, sketches, in a synthetic and complete exposition. Depending on specific logistics problems, it could be required to perform the oral exam by answering the questions by composing a written document, which will be discussed with the teacher.

The purpose of the oral test is to verify the knowledge underlying the study of rotordynamics and diagnostics, and the applications covered in the course, evaluating both the understanding of physical phenomena and their mathematical implementation (demonstration). The oral test also verifies the ability to transmit the results of the analyses carried out both in mathematical terms and with graphic representations.

 

Slides of the lessons, which include all the topics of the course, are provided via BeeP. The bibliography is suggested and can be fruitful consulted for individual in-depth analysis.


Bibliografia
Risorsa bibliografica obbligatoriaSl https://beep.metid.polimi.it/web/2016-17-rotor-dynamics-and-diagnostic-b-paolo-emilio-lino-maria-pennacchi-/attivita-online-e-avvisi
Note:

Slides of the lessons

Risorsa bibliografica obbligatoriaTadashi Tanuma, Advances in Steam Turbines for Modern Power Plants, Editore: Woodhead Publishing, Anno edizione: 2016, ISBN: 9780081003145
Note:

Available on www.biblio.polimi.it - The book is useful for the description of main components of typical rotating machines

Risorsa bibliografica facoltativaMichel Lalanne, Guy Ferraris Lalanne, Rotordynamics prediction in engineering, Editore: Wiley, Anno edizione: 1998, ISBN: 04-7197-288-6
Note:

Some hardcopies are available in Polimi libraries

Risorsa bibliografica facoltativaMaurice L . Adams, Rotating Machinery Vibration From Analysis to Troubleshooting , Editore: CRC Press, Anno edizione: 2000, ISBN: 978-0-203-90216-5 http://www.crcnetbase.com/isbn/9780824702588
Note:

Available on www.biblio.polimi.it

Risorsa bibliografica facoltativaChilds, Dara W., Turbomachinery rotordynamics : phenomena, modeling and analysis, Editore: Wiley, Anno edizione: 1993, ISBN: 04-7153-840-X
Note:

Some hardcopies are available in Polimi libraries

Risorsa bibliografica facoltativaAgnieszka Muszynska, Rotordynamics, Editore: CRC Press, Anno edizione: 2005, ISBN: 0-8247-2399-6 http://www.crcnetbase.com/isbn/9780824723996
Note:

Available on www.biblio.polimi.it

Risorsa bibliografica facoltativaAndrew D. Dimarogonas; Stefanos A Paipetis, Analytical Methods in Rotor Dynamics, Editore: Springer Netherlands, ISBN: 94-007-5904-5 http://link.springer.com/book/10.1007/978-94-007-5905-3/page/1
Note:

Available on www.biblio.polimi.it


Forme didattiche
Tipo Forma Didattica Ore di attività svolte in aula
(hh:mm)
Ore di studio autonome
(hh:mm)
Lezione
39:00
58:30
Esercitazione
21:00
31:30
Laboratorio Informatico
0:00
0:00
Laboratorio Sperimentale
0:00
0:00
Laboratorio Di Progetto
0:00
0:00
Totale 60:00 90:00

Informazioni in lingua inglese a supporto dell'internazionalizzazione
Insegnamento erogato in lingua Inglese
Disponibilità di materiale didattico/slides in lingua inglese
Disponibilità di libri di testo/bibliografia in lingua inglese
Possibilità di sostenere l'esame in lingua inglese
Disponibilità di supporto didattico in lingua inglese
schedaincarico v. 1.6.5 / 1.6.5
Area Servizi ICT
05/12/2020