The main reason is steam turbine consists of many rotating parts constitutes. The object of the analysis is to calculate the critical speeds of a rotor to find out if there are sufficient margins of separation between critical speed and the rotor operating speed. Area moments of inertia parallel axis theorem moment of inertia it of a circular area with respect to a tangent to the circle, 4 4 5 4 2 2 4 2 1 r it i ad r r r. How to download all of the lectures in pdf for a course in. Dynamic analysis of geared rotors by finite elements. The present course material is an outcome of an elective course on. Dynamics of rotor bearing systems using finite elements hasan g. This video explains the introduction to rotordynamic analysis.
It is commonly used to analyze the behavior of structures ranging from jet engines and steam turbines to auto engines and computer disk storage. This site is a gateway to technical literature on rotordynamics, including an online database of over 26,000 technical papers presented at conferences related to rotordynamics worldwide since 1974. You will find all pdfs and also as mp3 file for all video lectures which are in nptel. Seals very small rotorstator clearances flexible bearing supports rotor instability rotordynamics analysis aims at. A rotor is balanced by placing a cor rection mass of a certain size in a posi tion where it counteracts the unbal ance in the rotor. Rajiv tiwari,department of mechanical engineering,iit guwahati. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Each registered participant will be provided with a set of comprehensive lecture notes. The purpose of this book is to give a basic understanding of rotor dynamics. The principle of performing field balancing is to make usually tempo rary alterations to the mass distribu tion of the rotor, by. The last paragraph will discuss the influence of these bearings. Complete rotordynamics analysis with ansys, enabled by. In recent days, the study about rotor dynamics has gained more importance within steam turbine industries. But sometimes a system does not lend itself to this type of approximation and ansys has provided a unique solution in the industry to address it.
Cad import and automatic meshing library of elements all analysis types including prestress dedicated postprocessing multispool dynamics simulation direct connection to bearing codes account for the flexibility of the supporting structure andor the disks. Finally the dynamic response of a centrifugal pump depends on the behavior of suspending bearings. The rotor unbalance acts, therefore, in the lateral vibration mode, like an external exciting centrifugal force. Application notes static and dynamic balancing of rigid. Most of these courses consists 40 videos and 1 hour duration each.
Rotordynamic analysis is a crucial step in the development of rotor bearing systems. The dynamics of rotating structures are different from those of stationary structures. When the rotor mass centerline does not coincide with its rotational axis, then mass unbalanced inertiarelated rotating forces occur. Introduction to dynamics of rotorbearing systems includes numerous examples, from a singledegreeoffreedom system to complicated industrial rotating machinery, which serve to illustrate fundamental dynamic behaviors. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures. Starting of 3 phase induction motors, high starting torque motors, speed control, rheostatic method, pole changing method cascade control of speed, double cage. Mainly deals with the vibration of rotating structures. Next, through the supporting bearings and through the fluid encircling the rotor unless the rotor operates in vacuum, the rotor lateral vibrations are transmitted to the nonrotating parts of the machine. Ferrite magnets were traditionally used to make the permanent magnet pole pieces. Dynamics of rotorbearing systems using finite elements hasan g. Rotor dynamics is a system level analysis unlike the vibration analysis of the individual components. Rotor dynamics by jaafar alsalaet department of mechanical engineering college of engineering university of basrah 1.
This field is more than 140 year old and it is acquiring more attention day by day. Finite element methods for rotor dynamics springerlink. Based on the required magnetic field density in the rotor, the proper magnetic material is chosen to make the rotor. Rotor the rotor is made of permanent magnet and can vary from two to eight pole pairs with alternate north n and south s poles. Rotor dynamics teaching scheme credits marks distribution total l t p c marks theory marks practical marks ese ce ese ce 3 0 2 5 70 30 30 20 150 course content. Introduction to rotordynamic fe analysis, part1 youtube. Rot created by dyrobesrotor, this method is useful if you want to open an existing data file. Introduction and definitions rotor dynamics is the field of science that studies the response of rotating parts subjected to dynamic forces. Rotordynamics module analyze the dynamics of rotating machinery with the rotordynamics module. Machinery fault diagnosis and signal processing by prof. Basically, all the vibration phenomena will be valid, however, there are several differences and we have to set up new procedures for handling rotors and their vibratory phenomena.
Nptel, online courses and certification, learn for free. Here you can download the free fluid mechanics pdf notes fm pdf notes latest and old materials with multiple file links to download. New of dynamics of rotorbearing systems using finite. Most often, they represent the lowest modes of the entire machine structure. This background will be helpful in the identification of rotor bearing system parameters and its use in futuristic modelbased condition monitoring. The accurate prediction of dynamic characteristics, such as, critical speeds, natural whirl frequencies. Rotor dynamics offered to undergraduate, graduate and post graduate students at iit. A study was conducted to develop an implicit method for integrating the equations of motion of a lumpedmass model of a rotor bearing system.
A rotor dynamic model is developed by using finite element method fem, the rotor includes impellers, bearings and seals. Rigid rotor mounted on simple anistropic springs as bearings. Each line represents the frequency spectrum at a particular rotor speed. Introduction equations of motion structural analysis case studies references outline 2 27 1 introduction. Jul 01, 2018 this video explains the introduction to rotordynamic analysis.
Introduction to dynamics of rotor bearing systems includes numerous examples, from a singledegreeoffreedom system to complicated industrial rotating machinery, which serve to illustrate fundamental dynamic behaviors. Turbopump rotor dynamics because of high power density and low damping in rocket turbopumps, these machines exhibit in their most extreme form a variety of vibration effects, which are either absent or masked by normal damping mechanisms in other turbo machines. You can also get course completion certification for some of the courses. Coordinate systems, steady state rotor motion, elliptical motion. Rotor dynamics software manual download rotor dynamics software manual. As a result, the rotor responds with lateral vibrations with frequency, synchronous to rotational speed. Nptel provides elearning through online web and video courses various streams. The effects of axial torque were included by zorzi and nelson 37 and nelson 15 gave rotor dynamics elements with the timoshenko beam theory. Nov 30, 2010 nptel provides courseware in the form of video lectures and web courses. Rotor dynamics software manual downloadrotor dynamics software manual. Mohanty,department of mechanical engineering,iit kharagpur.
These conductor bars are short circuited by an end rings at both endof the rotor core. A practical guide to rotor dynamics applied machinery. Select tipselect tipspeed ratio higherspeed ratio higher. Url to the pdf file must be on exactly the same domain as the current web page. Free pdf download go to the directory where the file was downloaded and doubleclick the soavpu01580600us. Rotor dynamics analysis of a multistage centrifugal pump. Mod01 lec02 a brief history of rotor dynamics youtube. Calculate rotor diameter accounting for efficiency losses 44. Fluid mechanics pdf notes fm pdf notes smartzworld. Learn for free, pay a small fee for exam and get a certificate. The finite element method for rotors was first developed by ruhl and booker 29. Rotating shafts this type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case.
The accurate prediction of dynamic characteristics, such. Therefore paragraph three is devoted to these oscillations. Nx nastran rotor dynamics applications the following is a list of common industryspecific problems that can be analyzed using the nx nastran rotor dynamics application. It can be used in several different modes in critical industries such as power generation, oil and gas, process plants. It explains the critical speed, approach to solve rotordynamic analysis, balancing machine, campbell diagram, rotordynamic equations. Instead it is a cylindrical core constructed of steel laminations with conductor bars mounted parallel to the shaft and embedded near the surface of the rotor core. And for most rotor assemblies, this is still not only the most efficient, but the most accurate method. Finding critical speeds campbell diagrams calculating unbalance response calculating response to base excitation predicting rotor whirl and system stability simulating transient startup and. Rotordynamics, also known as rotor dynamics, is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. Moreover, it contains materials of some of the project works done by graduate. Nptel provides courseware in the form of video lectures and web courses. However, you may need to change the file properties and select the current and latest rotor. New of dynamics of rotorbearing systems using finite elements.
Whirl speed and stability analysis a revolution in rotor. Structural dynamics and vibration laboratory october 27, 2009. Double click the dyrobesrotor icon if you have created the shortcut, 4. To meet the weight and the cost requirements, the present day rotors are made extremely flexible.
This background will be helpful in the identification of rotorbearing system parameters and its use in futuristic modelbased condition monitoring. The approach was, first, to use a nordsiecklike numerical integration directly on the secondorder equations of motlon and, second. At its most basic level, rotor dynamics is concerned with one or more mechanical structures. The aim of this chapter is to elucidate a number of physical phenomena some of them counter intuitive which are typical of rotor dynamics. The study of the dynamic behavior of geared rotor systems usually requires that torsional and transverse vibratlon modes be coupled in the model, a. Turbopump rotor dynamics because of high power density and low damping in rocket turbopumps, these machines exhibit in their most extreme form a variety of vibration effects, which are either absent or masked by normal damping mechanisms in. Introduction even though there have been numerous studies on both rotor dynamics and gear dynamics, the studies on geared rotor dynamics have been rather recent. Nelson and mcvaugh 16 extended this to include gyroscopic effects. Figure 6 shows the typical situation when a compressor experienced instability. You can find them according to your branch and subject in the below link national mission on education through ict this was initiated by iit madras. Next, through the supporting bearings and through the fluid encircling the rotor unless the rotor operates in vacuum, the rotor lateral vibrations are transmitted to.
Fluid mechanics notes pdf fm notes pdf starts with the topics covering introduction to dimensions and units physical properties of fluids specific gravity, viscosity, surface tension. Design audits of machineryrotor dynamics another reason rotor instability can lead to large vibrations is because the rotors natural frequency is excited. Mohanty, department of mechanical engineering,iit kharagpur. Click here for more info by cloud goddess 20180415t23.