Dynamics of rotorbearing systems using finite elements. Apply to engineer, intern, product designer and more. Again, we will have three different versions with increasing bearing stiffness, and we will assume our support bearings have equal stiffness in all radial directions. The utilization of finite element models in rotor dynamics has. The concepts in the text are reinforced by parametric studies and numerous illustrative examples and figures. Turbocharger bearing support and rotor dynamics bearing.
A better understanding of rotor dynamics and support. Rotor dynamcis of a centrifugal pump technical university eindhoven, february 2006 5 2 whirl of simple rotors in rotor dynamics a common phenomenon is whirling. The accurate prediction of dynamic characteristics, such as, critical speeds, natural whirl frequencies, instability thresholds and response to mass unbalance, is important in the design of any type of rotating machinery. Systematic modeling of rotor dynamics for small unmanned. Combined blade element and momentum theories for non uniform inflow calculation. Therefore, rotordynamic analysis becomes a vital tool for. Rotordynamic analysis is a crucial step in the development of rotor bearing systems. Therefore, in the product development process, there is no change in the stage at which it occurs. Finite element equations of transverse vibration of. A rotor dynamic model is developed by using finite element method fem, the rotor includes impellers, bearings and seals.
Pdf the lecture introduces the basic problems in the rotordynamics of turbomachinery, excessive vibration and instability. The basic component of rotor dynamics is shaft or rotor. A machines overall reliablity depends heavily upon its underlying rotordynamic characteristics and their robustness. Free pdf download go to the directory where the file was downloaded and doubleclick the soavpu01580600us. Rotordynamics and finite element method is made use of, taking into consideration the continuous gyroscopic effect. Especially in machine and structural dynamics, we deal with the motion in. You can change your consent settings at any time by unsubscribing or as.
Solid model rotor dynamics is a method of performing the rotor dynamics analysis by solid elements instead of the conventional beam models. This field is more than 140 year old and it is acquiring more attention day by day. It also includes disc and the bearings which supports the rotor. Multispool dynamics simulation direct connection to bearing codes account for the flexibility of the supporting structure andor the disks connect directly to other ansys tools o the result. Nptel provides elearning through online web and video courses various streams. Rotordynamics software for predictive analyses of rotating. Rotor dynamics modeling programs mechanical acoustics. So, modal analysis of a pump rotor is of great concern to researchers, international standard organizations and industries. Rotating dynamics cylindrical modes since rotating machinery has to rotate to do useful work, lets consider what happens to the first mode of our rotor once it is spinning. Dynamics of rotors and foundations, erwin kramer, springerverlag berlin heidelberg 1993 vibration analysis of rotors, chongwon lee, center for noise and vibration control novic, korea, 1993, springer rotordynamics of automotive turbochargerslinear and nonlinear rotordynamics bearing design rotor. Rotor dynamic analysis of rm12 jet engine rotor using ansys deepak srikrishnanivas department of mechanical engineering blekinge institute of technology.
The possible cause is the change in the stiffness of the cracked rotor due to the concentration of strain energy in the vicinity of the crack. The goal is to provide a stepbystep approach to the understanding of fundamentals of rotor. Rotordynamics module analyze the dynamics of rotating machinery with the rotordynamics module. Kascak propulsion laboratory, avradcom research azd techuology laboratories lewis research cetzter clevelarzd, ohio national aeronautics and space administration scientific and technical information office 1980. 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.
Support global team on all steps of the rotorbearing systems design and dynamics analysis activities. Rotordynamics of automotive turbochargers springerlink. An improved method for calculating critical speeds and rotordynamics stability of turbomachinery by brian t. The primary purpose of the software is to illustrate features of rotating machines described in the. Timothy dimond, president, rotor bearing solutions international r bsi, formerly principal scientist of university of virginia rotating machinery and controls laboratory additional contributors. New of dynamics of rotorbearing systems using finite. Learn for free, pay a small fee for exam and get a certificate. Rotor dynamic analysis of rm12 jet engine rotor using ansys. Rotor dynamic analysis of rm12 jet engine rotor using ansys deepak srikrishnanivas department of mechanical engineering blekinge institute of technology karlskrona, sweden 2012 thesis submitted for completion of master of science in mechanical. The gyroscopic matrix, which depends on the rotational velocity or velocities of the analysis model.
Each line represents the frequency spectrum at a particular rotor speed. Rotor dynamics is specialized branch in which study includes the lateral and torsional vibration of rotating shaft. Rajiv tiwari,department of mechanical engineering,iit guwahati. Process description and product lifecycle stages solid model rotor dynamics is a method of performing the rotor dynamics analysis by solid elements instead of the conventional beam models. Rotor dynamics and finite element method is made use of, taking into consideration the continuous gyroscopic effect. Introduction and definitions rotor dynamics is the field of science that studies the response of rotating parts subjected to dynamic forces. Design audits of machineryrotor dynamics another reason rotor instability can lead to large vibrations is because the rotors natural frequency is excited. Turbocharger bearing support and rotor dynamics bearing support and dynamics of turbocharger rotors most of turbocharger tch rotors are supported in floatingring bearings fig. Strong theoretical background in dynamics of rotating. Therefore, dij will become a complex number, and the coefficients of the polynomial are lost. Fundamentals of rotorbearing dynamics and case histories in the rotating machinery industry third annual short course dates.
The rotor bars are not insulated from the rotor core because they are made of metals having less resistance than the core. It is the most valuable tool available for anyone working on modeling rotating machinery at the machine design stage or performing further analytical and experimental research on rotating machine dynamics. A better understanding of rotor dynamics and support stiffness if youre responsible for maintaining motors, you may have sent units off to be reconditioned, only to see them demonstrate high vibration levels once theyre back on the foundationand uncoupled to boot. We hope, that chair of the technical committee on rotor dynamics dr. Chen unmanned systems research group department of electrical and computer engineering, faculty of engineering national university of singapore, 21 lower kent ridge rd, singapore 119077 abstract this paper proposes a systematic modeling ap. Lees cambridge university press, 2010 rotordynamics software manual 1.
Computational techniques of rotor dynamics with the finite. Rotor dynamics meaning rotor dynamics definition rotor dy. This book is written as an introduction to rotorbearing dynamics for practicing engineers and students who are involved in rotor dynamics and bearing designs. Mohanty,department of mechanical engineering,iit kharagpur. In any contem porary computer program based on the lund method, s will be assigned a numerical complex value for each iteration of the algorithm. Mike swann, general manager, waukesha magnetic bearings 2. Feb 16, 2017 rotor dynamics meaning rotor dynamics definition rotor dy. As a part of a project on microjet engine design and manufacture, this paper describes in detail all the phases required to preliminary design of a onestage axial turbine. Dynamic analysis of geared rotors by finite elements ahmet kahraman, h. Nptel, online courses and certification, learn for free.
Rotor dynamics software manual downloadrotor dynamics software manual. By using the upf create new elements for nonlinear rotor dynamics. Brno, czech republic technical support for rotordynamics ing. It modifies the apparant stiffness of the model and can produce unstable. Army on rotor dynamics and bearing design for turboshaft engines used in helicopters. Fundamentals of rotorbearing dynamics and case histories. Introduction this software is a set of scripts written in matlab to accompany the above book. 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. The rotating damping matrix, also depends upon the rotational velocities. One neat thing about programs like adams and dads for that matter is that it it acausal in nature, unlike the blockbased environments simulink etc where you need to know how models interact when builind the model. Rotor dynamics software manual download rotor dynamics software manual. Table 3 shows the natural frequency for cracked and uncracked rotor system obtained through fem analysis.
Rotor dynamics analysis of a multistage centrifugal pump. The industrial revolution began with reciprocating steam engines as devised by james watt in 1780, and the 19th century witnessed a rapid expansion in various industrial sectors. Dynamic analysis of geared rotors by finite elements. Rieger in the survey report will inform about existence of the new theory of a rotor dynamics and will consider and will assess the new inertial theory of a rotor dynamics. Veldman strong interaction m1 viscous flow inviscid flow lecture notes in applied mathematics academic year 20112012. 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. Direct integration of transient rotor dynamics albert f. This book deals with rotordynamics of automotive turbochargers while encompassing the analysis of the dynamics of rotating machines at very high rotor speeds of 300,000 rpm and above. Finite element equations of transverse vibration of the spinning rocket is. Optimization of the parameters of the tilting pad bearings and rotor to minimize the power loss at bearings the bearing loads are not equal different stiffness and damping coefficients are input for. Field experience proves that the excessive vibration of the rotor of centrifugal pumps shows itself in wear and fatigue failure of shafts, bearings, wear rings, seals and impellers. Rotor dynamics by jaafar alsalaet department of mechanical engineering college of engineering university of basrah 1. The rotorbearing system is modeled in exactly the same.
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. Fundamentals of rotorbearing dynamics and case histories in. These bearings are undemanding from manufacturing point of view and at the same time have. Nonlinear coupling elementsbetween rotating and nonrotating parts oslide bearings oroller bearings osqueeze film dampers oseals ocontact model between rotating and nonrotating parts ocoupling by magnetic field oselflubricating bearing future. Be the first to see new rotor dynamics engineer jobs. Figure 6 shows the typical situation when a compressor experienced instability. Rotating shafts this type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case. Rotordynamics is the preeminent guide to rotordynamic theory and practice. Systematic modeling of rotor dynamics for small unmanned aerial vehicles limin wu, yijie ke and ben m. 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.