Rotordynamics module analyze the dynamics of rotating machinery with the rotordynamics module. Therefore paragraph three is devoted to these oscillations. Finding critical speeds campbell diagrams calculating unbalance response calculating response to base excitation predicting rotor whirl and system stability simulating transient startup and. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures. The principle of performing field balancing is to make usually tempo rary alterations to the mass distribu tion of the rotor, by. 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. Introduction to rotordynamic fe analysis, part1 youtube. 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.
Most of these courses consists 40 videos and 1 hour duration each. 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. Whirl speed and stability analysis a revolution in rotor. 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. Nptel provides elearning through online web and video courses various streams. Coordinate systems, steady state rotor motion, elliptical motion. Based on the required magnetic field density in the rotor, the proper magnetic material is chosen to make the rotor. The main reason is steam turbine consists of many rotating parts constitutes. The study of the dynamic behavior of geared rotor systems usually requires that torsional and transverse vibratlon modes be coupled in the model, a. Figure 6 shows the typical situation when a compressor experienced instability. Seals very small rotorstator clearances flexible bearing supports rotor instability rotordynamics analysis aims at. Nptel provides courseware in the form of video lectures and web courses. Dynamic analysis of geared rotors by finite elements.
Rotor dynamics by jaafar alsalaet department of mechanical engineering college of engineering university of basrah 1. A practical guide to rotor dynamics applied machinery. Nelson and mcvaugh 16 extended this to include gyroscopic effects. The approach was, first, to use a nordsiecklike numerical integration directly on the secondorder equations of motlon and, second. 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. Introduction equations of motion structural analysis case studies references outline 2 27 1 introduction. The rotor unbalance acts, therefore, in the lateral vibration mode, like an external exciting centrifugal force.
Ferrite magnets were traditionally used to make the permanent magnet pole pieces. Application notes static and dynamic balancing of rigid. Calculate rotor diameter accounting for efficiency losses 44. Complete rotordynamics analysis with ansys, enabled by. And for most rotor assemblies, this is still not only the most efficient, but the most accurate method. Most often, they represent the lowest modes of the entire machine structure. When the rotor mass centerline does not coincide with its rotational axis, then mass unbalanced inertiarelated rotating forces occur. Rotordynamic analysis is a crucial step in the development of rotor bearing systems. To meet the weight and the cost requirements, the present day rotors are made extremely flexible. Url to the pdf file must be on exactly the same domain as the current web page.
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. How to download all of the lectures in pdf for a course in. The effects of axial torque were included by zorzi and nelson 37 and nelson 15 gave rotor dynamics elements with the timoshenko beam theory. The purpose of this book is to give a basic understanding of rotor dynamics. Rotor dynamics offered to undergraduate, graduate and post graduate students at iit. 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. Starting of 3 phase induction motors, high starting torque motors, speed control, rheostatic method, pole changing method cascade control of speed, double cage. It is commonly used to analyze the behavior of structures ranging from jet engines and steam turbines to auto engines and computer disk storage. 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. At its most basic level, rotor dynamics is concerned with one or more mechanical structures. Finite element methods for rotor dynamics springerlink. You can also get course completion certification for some of the courses. Double click the dyrobesrotor icon if you have created the shortcut, 4.
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. Rigid rotor mounted on simple anistropic springs as bearings. A study was conducted to develop an implicit method for integrating the equations of motion of a lumpedmass model of a rotor bearing system. 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.
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. Here you can download the free fluid mechanics pdf notes fm pdf notes latest and old materials with multiple file links to download. Introduction and definitions rotor dynamics is the field of science that studies the response of rotating parts subjected to dynamic forces. Nov 30, 2010 nptel provides courseware in the form of video lectures and web courses. Rotor dynamics is a system level analysis unlike the vibration analysis of the individual components. Design audits of machineryrotor dynamics another reason rotor instability can lead to large vibrations is because the rotors natural frequency is excited. 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. Nptel, online courses and certification, learn for free. Mohanty, department of mechanical engineering,iit kharagpur. 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. Finally the dynamic response of a centrifugal pump depends on the behavior of suspending bearings. The accurate prediction of dynamic characteristics, such as, critical speeds, natural whirl frequencies. Select tipselect tipspeed ratio higherspeed ratio higher. In recent days, the study about rotor dynamics has gained more importance within steam turbine industries.
Click here for more info by cloud goddess 20180415t23. It explains the critical speed, approach to solve rotordynamic analysis, balancing machine, campbell diagram, rotordynamic equations. 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. Moreover, it contains materials of some of the project works done by graduate. Rot created by dyrobesrotor, this method is useful if you want to open an existing data file. 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. The present course material is an outcome of an elective course on. This field is more than 140 year old and it is acquiring more attention day by day.
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. Rotordynamics, also known as rotor dynamics, is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. The accurate prediction of dynamic characteristics, such. Rotor dynamics analysis of a multistage centrifugal pump. The last paragraph will discuss the influence of these bearings.
New of dynamics of rotorbearing systems using finite elements. The dynamics of rotating structures are different from those of stationary 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. Each line represents the frequency spectrum at a particular rotor speed. Dynamics of rotorbearing systems using finite elements hasan g. Structural dynamics and vibration laboratory october 27, 2009. Rotor dynamics software manual downloadrotor dynamics software manual. A rotor dynamic model is developed by using finite element method fem, the rotor includes impellers, bearings and seals. 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. However, you may need to change the file properties and select the current and latest rotor. 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.
As a result, the rotor responds with lateral vibrations with frequency, synchronous to rotational speed. Rotating shafts this type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case. 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. New of dynamics of rotorbearing systems using finite. 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. 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. Mod01 lec02 a brief history of rotor dynamics youtube. These conductor bars are short circuited by an end rings at both endof the rotor core. It can be used in several different modes in critical industries such as power generation, oil and gas, process plants. This background will be helpful in the identification of rotorbearing system parameters and its use in futuristic modelbased condition monitoring. Jul 01, 2018 this video explains the introduction to rotordynamic analysis. Rajiv tiwari,department of mechanical engineering,iit guwahati. The aim of this chapter is to elucidate a number of physical phenomena some of them counter intuitive which are typical of rotor dynamics. You will find all pdfs and also as mp3 file for all video lectures which are in nptel.
Learn for free, pay a small fee for exam and get a certificate. Fluid mechanics pdf notes fm pdf notes smartzworld. Each registered participant will be provided with a set of comprehensive lecture notes. The finite element method for rotors was first developed by ruhl and booker 29.
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