Predict the dynamic response of rotating systems such as shafts, turbines and propellers. Proximity probe measurements of rotor vibration provide vast insight into the health of rotating machinery. When calculating rotor dynamics in conjunction with bearing housings it is possible to use both modern production software and programs for beam modeling. I dont know how the code valutes the stiffness of the system, so i tried both to put the parameters of the disc in the voice disc and in the voice elements. This measurement is not needed for balancing the rotor, but will be used later as a check on calculations. Glenn research center, cleveland, ohio ards analysis of rotordynamic systems is a publicdomain computer program that simulates transient and steadystate dynamics of a rotary machine that can include as many as five interconnected flexible shafts. The field of rotor dynamics is concerned with study of dynamic and stability characteristics of the rotating machinery and plays an important role in the improving safety and performance of the entire systems that they are part of.
A flexible rotor will require multiplane balancing. Coupling effects between lateral and torsional vibrations in the gear. Rma develops and supports software for rotating machinery analysis. Using our stateoftheart analysis codes see engineering software, calculations such as critical speeds, stability, and damped response are used with new designs or to diagnose problems with existing equipment. At its most basic level, rotor dynamics is concerned with one or more mechanical structures supported by bearings and influenced by internal phenomena that rotate around a single axis. When calculating the rotor dynamics of systems with hydrodynamic bearings, the nonlinear fluid film forces are reduced to linearize stiffness and damping coefficients.
Once the shaft train model has been assembled it can be visualised. Effect of shaft manufacturing bending deviation on dynamic. June 1, 2001 software program for simulating rotor dynamics on personal computers john h. The video gives a general introduction to the rotor dynamics software. 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. Effect of bearing housings on centrifugal pump rotordynamics. The dynamics r4 program system is designed for solution of a broad spectrum of multishaft rotor dynamical problems in linear and. In this paper, rotor shaft with continuously varying crosssectional area is presented. The program can be used to calculate the effects of the crack on the shaft system natural frequencies. Development of software versions dynamics r4, alfatranzit co. Once you have taken all these steps, the model may need to be refined according to the data that is collected during mechanical testing if the critical speeds differ by more than 5%. This 12minute video explains why dyrobes is the most complete and advanced rotor dynamics software on the market. The solid rotor interface for modeling a rotor as a full 3d geometric model made with cad software or using the builtin cad capabilities of comsol multiphysics. Further, most of the works on rotating systems have been done with particular cylindrical element type shaft rotor with uniform crosssectional area.
Rotor dynamics analysis rotating machinery consulting. Flexible shafts are detailed as such by the manufacturers and must be multiplane balanced as described in iso 2194012 or equivalent. Development of software versions changes in dynamics r4. Basic torsional analysis with the rotor dynamics software madyn.
Rotor model variable temperature the worldwide leader in software for rotating machinery dynamics armd v6. This is considerably easier when your software for modeling bearings, seals, and the machines aerodynamic properties are all connected to your rotor dynamics tool. This dynamic analysis of the rotor shows that the pump shaft, the coupling and the motor shaft as one unit are free from any torsional critical speed according to the api 610 11th edition criterion. Rotor dynamics predict the dynamic response of rotating systems such as shafts, turbines and propellers. At its most basic level, rotor dynamics is concerned with one or more mechanical structures supported by. Browse through a list of free utilities, drivers, software, and links to topicrelated sites. This onehour online training will present the basics of rotor. The rotor system is rotating with a constant rotational speed, see figure 2 figure 2 a jeffcott rotor. Rotor dynamics is the branch of engineering that studies the lateral and torsional vibrations of rotating shafts, with the objective of predicting the. The shaft design is safe based on above calculations.
New command invert link connection is now available in the link context menu. A rotor system is modeled as a massless, elastic shaft supported by two nonflexible bearings. Complete rotordynamics analysis with ansys, enabled by. Balance correction is most effective when it is applied at or on the component that actually has the unbalance. The machinery fault simulator mfs family is designed to study the signature of common machinery faults, such as unbalance, alignment, resonance, bearing, rotor dynamics, crack shaft, gearbox, belt drive, reciprocating mechanism, mechanical rub, induction motor, pump, compressor, and fan. This type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case. Rotordynamic plots can be complex, and characteristics can often be explained by more than one theory or cause. Shock and vibration information center critical speeds and response of flexible rotor systems. Rotor dynamics our core competency is the accurate prediction of the dynamics of multi shaft rotating systems. The rotordynamics module provides five dedicated physics interfaces that you can use to accurately model rotors and bearings. Concept of critical speed of shaft rotor dynamics dynamics of machinery duration. The study of the dynamic behavior of geared rotor systems usually requires the coupling between torsional and transverse vibration modes to be included in the model, although this is. The software combines an intuitive windowsbased interface. The dynamics r4 program system is designed for solution of a broad spectrum of multishaft rotor dynamical problems in linear and nonlinear statement.
Developed for the working engineer, dyrobes offers complete. Madyn 2000 is a leading rotordynamics software developed by delta. Application notes static and dynamic balancing of rigid. Our systems include machinery fault simulators, interactive training program, data acquisition hardware, software and accessories. For a statically indeterminate rotor, a bearing or seal can be arbitrarily misaligned, changing the bearing loads and for a hydrodynamic bearing changing the rotordynamic coefficients and response. Shaft trains with epicyclic gears, where the planet carrier can either be stationary or rotating. 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 resulting system natural frequencies are calculated and a comparison can be made to the uncracked system natural frequencies.
A rigid rotor can be balanced at the two end planes and will stay in balance when in service. The following is a list of common industryspecific problems that can be analyzed using the nx nastran rotor dynamics application. Dynamics r4 is a new program system of alfatranzit co. See what you can model with the rotordynamics module from comsol. The rotor is for a prototype highspeed electrical machine and the testing of the machine will only be done to check the electromagnetic performance so the only mass the bearings are required to suspend is the mass of the rotor itself. A color and transparency control has been added to the gearset visualisation properties. Since 1994, rma has been helping engineers model and analyze rotating equipment quickly, efficiently, and reliably. Rotordynamics, also known as rotor dynamics, is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. Rotating machinery rotor balancing lifetime reliability. A selector for visualisation only a particular gear in a large gearset has been added to the interface.
Rotordynamics software for predictive analyses of rotating. For the example of the spur geared rotor system, the translational degree of freedom dof in the xdirection is neglected in both nodes and correspondingly there are 5 dofs in each node as shown in figure 5. In the video the torsional rotor dynamic analysis of a compressor train with the software madyn 2000 is shown. Kahraman1 dynamic analysis of geared rotors by finite. Vibration analysis of pump shaft using finite element analysis software. When steady forces in a stationary frame are drawn in a similar figure, the forces correspond better with each other. Rotating systems are subject to gyro scopic forces such as coriolis and centrifugal forces that are not present in stationary systems. General introduction to the rotor dynamics software madyn 2000. October 1215, 2020, cologne, germany a 4day seminar and workshop for engineers and technical managers involved in rotating machin ery design, operation, main tenance, diagnosis, and troubles hooting. Rotor dynamics rotorbearingssupports lateral vibration. The results are very different and i dont know which one is correct. Effect of a planetary gearbox on the dynamics of a rotor system. Singhal, in 10th international conference on vibrations in rotating machinery, 2012. Introduction this software is a set of scripts written in matlab to accompany the above book.
The inclusion of the stiffness of bearing housing designs will allow to determine rotor dynamics of the barrel casing centrifugal boiler feed pump rotor more precisely. Understanding vibration for rotating machinery diagnostics. Rostab, rotormap, rosync and roresp integrated by rotlats user interface. One possible cause is the influence of the dynamical response of the shaft on the measurements.
As a result, they will feel the effect of rotor dynamics based on components such as seals. A disk with a known mass unbalance is placed in the middle. Basic torsional analysis with the rotor dynamics software. Dauvillier 4014 iscorma 2001 dynamic behavior of highspeed rotor supported. Iscorma 2001 dynamics of rotating flexible bladedisc shaft assemblies application to a turbomolecular pump rotor g. The pump is not disturbed by any critical speeds during running. They used harmonic balance method for this purpose. The finite shaft element has two nodes, namely, o 1 and o 2, used to obtain the differential equations of motion. The primary purpose of the software is to illustrate features of rotating machines described in the book, in particular the lateral motion based on shaft line models. Developed for the working engineer, dyrobes offers complete rotordynamic analysis, vibration analysis, bearing performance and balancing calculations based in finite element analysis.
If a rotor is balanced on a low speed balancing machine. Unique and specific problems will be presented and its solution illustrated in. Rotordynamics software for predictive analyses of rotating machines. Not all these machines are considered turbomachinery, but they all rotate at high speeds. Rotor dynamics software, dynamics r4, alfatranzit co.
The dyrobes difference combining power with ease of use. A jeffcott rotor model is often used to explain the whirling effect. Armd advanced rotating machinery dynamics is a new generation. Rotor dynamics analysis of a multistage centrifugal pump. Besides the journal bearing and shaft characteris tics, the dynamic characteristics of the seals and the impeller diffuser interaction can have significant effects on the critical speed location, rotor unbalance sensitivity, and rotor stability. Rotor dynamics analysis is an important calculation step to design efficient and reliable rotating equipment. However, it can be difficult to determine the right inspection or remedial plans based on vibration data alone. Predictive analysis can lead to better rotating machinery designs. The rotor dynamics package uses a finiteelement based formulation for performing damped and undamped lateral natural frequencies, mode shapes, stability, unbalance response, and timetransient response of rotating systems. Spatial location of subsystems free orientation of spin axes.