Introduction To Dynamics Of Rotor Bearing Systems

This book is written as an introduction to rotor-bearing dynamics for practicing engineers and students who are involved in rotordynamics and bearing design. The goal of this book is to provide a step-by-step approach to the understanding of fundamentals of rotor-bearing dynamics by using DyRoBeS(c) . Therefore, the emphasis of this book is on the basic principals, phenomena, modeling, and interpretation of the results. Numerous examples, from a single-degree-of-freedom system to complicated industrial rotating machinery, are employed throughout this book to illustrate these fundamental dynamic behaviors. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures. The book begins with a brief discussion of the mathematical modeling of physical dynamic systems and an overview of the basic vibration concepts in Chapter 1. The coordinate systems and the kinematics of the rotor motion are presented in Chapter 2. A simple two-degrees-of-freedom rotor system, the Laval-Jeffcott rotor model, is utilized in Chapter 3 to demonstrate many important phenomena in rotordynamics. This simple 2DOF model provides many valuable physical insights into more practical and complicated systems. Chapter 4 discusses the rotating disk equations and rigid rotor dynamics. Chapter 5 covers the finite element formulation for a rotating shaft element. Chapter 6 deals with various types of bearings, dampers, seals and other interconnection components. All the reaction forces from these components are non-linear in nature. The concept of linearization around the static equilibrium is discussed. Chapter 7 summarizes the lateral vibration study with several practical examples. Various solution techniques and interpretation of the results are discussed. Chapter 8 is devoted to the important subject of torsional vibration. Finally, a brief description of the balancing method, influence coefficient method is presented in Chapter 9.

The purpose of this book is to give a basic understanding of rotor dynamics phenomena with the help of simple rotor models and subsequently, the modern analysis methods for real life rotor systems. This background will be helpful in the identification of rotor-bearing system parameters and its use in futuristic model-based condition monitoring and, fault diagnostics and prognostics. The book starts with introductory material for finite element methods and moves to linear and non-linear vibrations, continuous systems, vibration measurement techniques, signal processing and error analysis, general identification techniques in engineering systems, and MATLAB analysis of simple rotors. Key Features: • Covers both transfer matrix methods (TMM) and finite element methods (FEM) • Discusses transverse and torsional vibrations • Includes worked examples with simplicity of mathematical background and a modern numerical method approach • Explores the concepts of instability analysis and dynamic balancing • Provides a basic understanding of rotor dynamics phenomena with the help of simple rotor models including modern analysis methods for real life rotor systems.

Rotordynamics are of great importance in the design, manufacture and assembly of turbomachines as well as in ensuring their safe operation. Also important are the dynamics of the foundation and its interaction with the dynamics of the rotor. This book is divided into four parts. Following a presentation of the basic theory the dynamics of rotors supported on several bearings. The third part describes the dynamics of foundations of turbine line-outs and the calculations for a turbomachine coupled with its foundation. The last part includes a section on estimation procedures, a comprehensive presentation of the theoryand practice of rotors having a transverse crack, a section on the mathematical fundamentals and a description of the computer program used for the examples in the book. The book addresses both the practical engineer and the theoretician and should provide manufacturers, operators, university and polytechnic lecturers and students with an understanding of the vibrations of turbomachines. The results are described in such a way that they can be easily understood and applied.

The Third Revised And Enlarged Edition Of The Book Presents An In-Depth Study Of The Dynamic Behaviour Of Rotating And Reciprocating Machinery. It Evolved Out Of Lectures Delivered At Different Universities Over The Last Two Decades. The Book Deals With Torsional And Bending Vibrations Of Rotors, Stability Aspects, Balancing And Condition Monitoring. Closed Form Solutions Are Given Wherever Possible And Parametric Studies Presented To Give A Clear Understanding Of The Subject. Transfer Matrix Methods Is Extensively Used For General Class Of Rotors For Both Bending And Torsional Vibrations.Special Attentions Are Given To Transient Analysis Of The Rotors Which Is Becoming An Essential Part Of The Design Of High Speed Machinery. Systems With Fluid Film Bearings, Cracked Rotors And Two Spool Rotors Are Also Presented.A First Course On Theory Of Vibration Is A Prerequisite To This Study. Analysis Used Is Fairly Simple, But Sufficiently Advanced To The Requisite Level Of Predicting Practical Observations. As Far As Possible, Practical Examples Are Illustrated, So That The Book Is Also Useful To Practising Engineers.A Special Feature Of This Book Is Diagnostics Of Rotating Machinery Using Vibration Signature Analysis And Application Of Expert Systems To A Field Engineer In Trouble Shooting Work.

Rotor dynamics is an important branch of dynamics that deals with behavior of rotating machines ranging from very large systems like power plant rotors, for example, a turbogenerator, to very small systems like a tiny dentist’s drill, with a variety of rotors such as pumps, compressors, steam/gas turbines, motors, turbopumps etc. as used for example in process industry, falling in between. The speeds of these rotors vary in a large range, from a few hundred RPM to more than a hundred thousand RPM. Complex systems of rotating shafts depending upon their specific requirements, are supported on different types of bearings. There are rolling element bearings, various kinds of fluid film bearings, foil and gas bearings, magnetic bearings, to name but a few. The present day rotors are much lighter, handle a large amount of energy and fluid mass, operate at much higher speeds, and therefore are most susceptible to vibration and instability problems. This have given rise to several interesting physical phenomena, some of which are fairly well understood today, while some are still the subject of continued investigation. Research in rotor dynamics started more than one hundred years ago. The progress of the research in the early years was slow. However, with the availability of larger computing power and versatile measurement technologies, research in all aspects of rotor dynamics has accelerated over the past decades. The demand from industry for light weight, high performance and reliable rotor-bearing systems is the driving force for research, and new developments in the field of rotor dynamics. The symposium proceedings contain papers on various important aspects of rotor dynamics such as, modeling, analytical, computational and experimental methods, developments in bearings, dampers, seals including magnetic bearings, rub, impact and foundation effects, turbomachine blades, active and passive vibration control strategies including control of instabilities, nonlinear and parametric effects, fault diagnostics and condition monitoring, and cracked rotors. This volume is of immense value to teachers, researchers in educational institutes, scientists, researchers in R&D laboratories and practising engineers in industry.

Includes bibliographical references and index.