Rotordynamics, also known as rotor dynamics, is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. Rotordynamics module analyze the dynamics of rotating machinery with the rotordynamics module. Data collection and analysis software development for rotor dynamics testing in spin laboratory. The third revised and enlarged edition of the book presents an in depth study of the dynamic behaviour of rotating and reciprocating machinery.
The rotor dynamics spin laboratory at nasa glenn is designed such as it has the capabilities to spin a subscale test article rotor disk with a maximum outside diameter of 23. Rotor dynamics by jaafar alsalaet department of mechanical engineering college of engineering university of basrah 1. Dynamic analysis of geared rotors by finite elements. Pdf analytical investigation of the dynamics of cracked. 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. The rotating damping matrix, also depends upon the rotational velocities.
Measurement of rotordynamic coefficients for a hyd rostatic. Formulation of a transfer function between rotor responses. Then a method to implement the flow forces to the rotor finite element model as a. Turbocharger bearing support and rotor dynamics bearing. The contents in the hlp and chm files are identical. Data collection and analysis software development for. Rotor dynamics is a system level analysis unlike the vibration analysis of the individual components. Often it can be observed in practice, which makes this physically easy to interpret. Empowering our customers with xlrotor, you can analyze any rotating machine quickly and accurately. A rotor is balanced if its vibration amplitude is lower than the threshod of 25 micrometers peak topeak n proximty of the first or second critical speed, as established by iso and api2, 3, 11. This paper presents results from experimental and analytical studies on rotor tostationary element partial rubbings at several locations and their effects on rotor dynamic responses. Timothy dimond, president, rotor bearing solutions international r bsi, formerly principal scientist of university of virginia rotating machinery and controls laboratory additional contributors. Lund in the analysis of rotor dynamics the influence of fluid film bearings often plays a decisive role. The gyroscopic matrix, which depends on the rotational velocity or velocities of the analysis model.
The study of the dynamic behavior of geared rotor systems usually requires that torsional and transverse vibratlon modes be coupled in the model, a. Analytical methods in rotor dynamics free download as pdf file. Fundamentals of rotorbearing dynamics and case histories. Lateral vibration of a shaft rotor is due to instability, unbalance, or other forces acting on the rotor. Lateral vibration analysis vibration, dynamics and noise. 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. If the rotor is not properly balanced, it vibrates as speed increases and may cause mechanical damages.
Since 1994, rma has been helping engineers model and analyze rotating equipment quickly, efficiently, and reliably. The aim of this chapter is to elucidate a number of physical phenomena some of them counter intuitive which are typical of rotor dynamics. Dimarogonas and others published analytical methods in rotor dynamics. Chapter 2variable elasticity effects in rotatingmachineryabstract the effects of variable elasticity in rotating machinery occur with alarge variety of mechanical, electrical, etc. Verification between ansys and analytical model with bearing. 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. Rotor dynamcis of a centrifugal pump technical university eindhoven, february 2006 52 whirl of simple rotors in rotor dynamics a common phenomenon is whirling.
Several analytical results of the examples will be shown. Rotordynamic analysis is a crucial step in the development of rotor bearing systems. Abstract one of the methods to find the natural frequencies of rotating systems is the application of the transfer matrix method. Small rotor vibrations result in low stresses on the shaft, bearings and surrounding equipment. Introduction and definitions rotor dynamics is the field of science that studies the response of rotating parts subjected to dynamic forces.
Review of analytical methods in rotorbearing dynamics. At its most basic level, rotor dynamics is concerned with one or more mechanical structures. Page 2 joint on dynamic behavior of rotor bearing system and compare the findings with the results obtained from the same rotor bearing system without a bolted joint. Of particular concern is the modeling of breathing cracks, which open and close due to the selfweight of the rotor, producing a parametric excitation. The zip and tgz files are identical, except that on linux, unix, and macos, unpacking. The help files are provided in two formats, hlp and chm. A rigid rotor requires to be evenly positioned about its axis so that it may run true. Vibration monitoring helps in reducing the machine down time. Rotating shafts this type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case. Page 2 joint on dynamic behavior of rotorbearing system and compare the findings with the results obtained from the same rotorbearing system without a bolted joint. Xlrotor is the worlds best rotordynamic software because it blends unmatched easeofuse with extensive analytical features. Five basic analytical methods with may variations of each have been developed to calcu late critical speeds of rotor shafts. In this paper has investigated the hinged model method for the cracked rotors, then get the resulting dynamics for model of breathing cracks, the crack opens and closes because of tension and. Most often, they represent the lowest modes of the entire machine structure.
The author likes hlp format, however, the latest default format by microsoft is chm format. Pdf mathematical models for rotor dynamic analysis. Rotordynamisk analys av 3dmodellerad gasturbinrotor i. Proceedings 7th iftommconference on rotor dynamics, vienna, austria, pp. Design audits of machineryrotor dynamics 2 vibration principles and phenomena throughout a machines operating range and life between turnarounds, maintaining small rotor vibration amplitudes is our basic desire. The bearings provide the major source of damping, thereby controlling the peak amplitude response, and their stiffness properties affect the critical speeds and the stability of the rotor. Unexpected server response 403 while retrieving pdf. The dynamics of rotating structures are different from those of stationary structures. Rotor dynamics software manual download rotor dynamics software manual. The experimental analysis of vibration monitoring in system.
Browse through a list of free utilities, drivers, software, and links to topicrelated sites. Rma develops and supports software for rotating machinery analysis. Lagranges equation and its application a brief introduction d. The rotor dynamics spin laboratory at nasa glenn is designed such as it has the capabilities to spin a subscale test.
The mathematical model of a rubbing rotor is given. Structural dynamics and vibration laboratory october 27, 2009. Rotor dynamics is important in designing a gas turbine rotor because bad dynamics can easily. Rotordynamic analysis of bolted diskdrum rotor with. Unique and specific problems will be presented and its solution illustrated in. Dynamics of rotorbearing systems using finite elements hasan g. Review of analytical methods in rotor bearing dynamics j. These bearings are undemanding from manufacturing point of view and at the same time have. There is a growing tendency today to extract information about the prognostic parameters based on system analysis through various diagnostic techniques to assess the health of the plant or equipment.
Complete rotordynamics analysis with ansys, enabled by. It modifies the apparant stiffness of the model and can produce unstable. This paper will look at methods that have been used to model cracked rotors, and summarize the resulting dynamics. The zip and tgz files are identical, except that on linux, unix, and macos, unpacking the tgz file ensures. Rotordynamic analysis of bolted diskdrum rotor with contact nonlinearity manuscript id. Data collection and analysis software development for rotor. Overview of the nx nastran rotor dynamics capabilities.
Dynamic analysis of complex rotor forms became a necessity, while the importance of approximate methods for dynamic analysis was stressed. Rotor dynamics as a tool for solving vibration problems. Measurement of rotordynamic coefficients for a hyd. To meet the weight and the cost requirements, the present day rotors are made extremely flexible. Analytical methods in rotor dynamics 2nd edition books. Bent ley rotor dynamics research corporation minden, nevada 89423, u.
Numerical and analytical analysis of elastic rotor. One requirement for proper balancing of the rotor is even distribution of rotor mass about the center line for minimal resultant vibration. Mathematical background in modeling and simulation methods is necessary. New of dynamics of rotorbearing systems using finite. The accurate prediction of dynamic characteristics, such. Measurement of rotordynamic coefficients for a hyd rostatic radial bearing b. The book addresses both practitioners working in the field of rotordynamics of automotive turbochargers and graduate students in mechanical engineering. Analytical methods in rotor dynamics linkedin slideshare.
Typically, modeling methods for such system include system identi. Finally, the emergence of fracture mechanics, as a new branch of applied mechanics, provided analytical tools to investigate crack influence on the dynamic behavior of rotors. Center of excellence in dynamics, robotics, and automation, sharif university of technology, tehran 1659567, iran. 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. 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 purpose of this thesis work is to analyze a tool for rotor dynamics calculations. Analytical methods in rotor dynamics second edition andrew d. In this method the rotor is modeled as several elements along the. 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 number of degrees of freedom in this discretization is r. Systematic modeling of rotor dynamics for small unmanned.
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. 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. This paper presents results from experimental and analytical studies on rotortostationary element partial rubbings at several locations and their effects on rotor dynamic responses. The experimental analysis of vibration monitoring in. 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. Wagner rockwell international, rocketdyne division, canoga park, ca 94 measurement of rotordynamic coefficients is presented for a pair of hydrostatic radial bearings, including direct and crosscoupled stiffness and damping. Chondros analytical methods in rotor dynamics 2nd edition published. Analytical methods in rotor dynamics second edition. Gasch introduced the finite element method to rotordynamics. These methods will then be numerically applied firstly to a simple rotor configuration rotating at constant speed, and finally isf will be applied to a rotor model based on the propfan engine developed in the scope of the duprin european project. Stability and vibration analysis of a complex flexible. 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. Turbocharger bearing support and rotor dynamics bearing support and dynamics of turbocharger rotors most of turbocharger tch rotors are supported in floatingring bearings fig.
Reduction to the analysis set for the direct methods. It evolved out of lectures delivered at different universities over the last two decades. Whirl speed and stability analysis a revolution in rotor. The bearings provide the major source of damping, thereby controlling the peak amplitude response, and their stiffness properties affect the critical speeds and the stability of. Free pdf download go to the directory where the file was downloaded and doubleclick the soavpu01580600us. This field is more than 140 year old and it is acquiring more attention day by day. Ansys classic version 11 is the analyze program that is going to be evaluated for the rotor dynamic applications.
The design and construction of rotating machinery operating at supercritical speeds was, in the 1920s, an event of revolutionary importance for the then new branch of dynamics known as rotor dynamics. Mike swann, general manager, waukesha magnetic bearings. The purpose of this course material is to give a basic understanding of the rotor dynamics phenomena with the help of a few simple rotor models and modern analysis methods for reallife rotor systems. If you have a new computer with latest windows operation system and can not open hlp help file, you may. Rotor dynamics is important in designing a gas turbine rotor because bad dynamics can easily lead to disaster. Lateral analysis also called rotordynamics analysis simulates the rotating system, calculates the critical speeds, predicts vibration amplitudes, and provides recommendations to reduce vibration risks. Introduction equations of motion structural analysis case studies references outline 2 27 1 introduction. Rotordynamic analysis of bolted diskdrum rotor with contact.
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