Virtual design software for mechanical system dynamics using. At its most basic level, rotor dynamics is concerned with one or more mechanical structures. Transfer matrix optical modeling stanford university. With the range of study types included in the rotordynamics module, you can properly analyze the dynamics of a rotor assembly using different analysis techniques that are adapted to the characteristics of rotordynamics phenomena. The rotordynamics module enables you to account for gyroscopic effects, including frame acceleration forces. At its most basic level rotor dynamics is concerned with one or more mechanical structures supported by bearings and. An improved method for calculating critical speeds and rotordynamics stability of turbomachinery by brian t. Chapter2 rudiments of rotor dynamics introduction, s.
Pump rotordynamics is introduced noting the major difference with other rotating systems, i. Flapwise vibration computations of coupled helicopter. The transfer matrix method can be used for the analysis of the wave propagation of. Rotordynamics 1 deal with dynamics of rotating machines. The transfer matrix method tmm was developed for a long time and used widely in structure mechanics and rotor dynamics of the linear timeinvariant system. Rotor dynamics is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. The transfer matrix method mentioned above is to analyze the dynamic. At present, there are significant contributions to the literature of improving the mathematical modeling and analysis of rotorcraft. The first problem is illustrated by figures 5 and 6. Jorgen lund, who worked for prohl, programmed the transfer matrix method in fortran on their new.
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. Holzer3 initially applied tmm to solve the problems of torsion vibrations of rods. The transfer matrix method represents a general flexible rotor by a number of. Rotor dynamics software, packages, training, purchasing. Accuracy of the riccati transfer matrix method in rotor dynamic analysis. Transfer matrix method for natural vibration analysis of. One very attractive aspect of this technique is that any program which can perform. Kahraman1 dynamic analysis of geared rotors by finite. Rotor dynamics of the barrel casing centrifugal boiler feed pump rotor depends on various entities. The finite element method is the most robust method and can. Schematic diagrams of a misaligned rotor for a the global offset, and b the con.
It uses a modal representation of the rotor models and. Extension of the transfer matrix method for rotordynamic. Rotor dynamics analysis is an important calculation step to design efficient and reliable rotating equipment. The third revised and enlarged edition of the book presents an indepth study of the dynamic behaviour of rotating and reciprocating machinery. March, 2011 this document describes, briefly, how to use the matlab script, transfermatrix. Mw gas turbine system, the transfer matrix method of rotor dynamics was employed. Hollow tapered shaft rotors with uniform thickness and uniform bore are considered. There are currently three rotor dynamics software suites based on the finite element method, written in matlab. Virtual design software for mechanical system dynamics using transfer matrix method of multibody system and its application haigen yang1, xiaoting rui2, zhihuan zhan3, jiansu zhang2, junjie gu2 and bin he4 abstract the complex mechanical systems such as highspeed trains, multiple launch rocket system, selfpropelled artillery, and. Rotordynamic analyses using finite element method a thesis. New method for dynamics modelling and analysis on flexible plate undergoing large overall motion. The simulation experiment results show that, in the calculation of highorder critical. Rotordynamics software for predictive analyses of rotating.
The concept of the transfer matrix method is well established and understood, having been. Transfer matrix method software free download transfer. Transfer matrix method, free transfer matrix method software downloads, page 2. Dynamic analysis of geared rotors by finite elements ahmet kahraman, h. Approaches to dynamic analysis of rotor systems can be divided into two main branches. It is very difficult to compute the system dynamics of an 11 bearing turbinegenerator system using transfer matrix methods.
Two such rotor section shapes are considered in this paper. Proceedings of the asme 1998 international gas turbine and aeroengine congress and exhibition. Rma develops and supports software for rotating machinery analysis. Shafts or circular crosssection beams are important parts of rotating systems and their geometries play important role in rotor dynamics.
They concluded that, under the force load, the gyroscopic effect not only increases the critical axial force, but also changes the instability type from divergence to flutter. Pdf transfer matrix method to vibration analysis of rotors with. The basic equations for the modeling of linear rotorbearing systems are given along with an example for the rotordynamics of a multiple stage compressor. Taken a gas turbine rotor system as the research object, this paper has established dynamical model based on transfer matrix method. Rotordynamics, also known as rotor dynamics, is a specialized branch of applied mechanics concerned with the behavior and diagnosis of rotating structures. Virtual design software for mechanical system dynamics.
Rotor dynamics software, dynamics r4, alfatranzit co. Some of the studies used the transfer matrix method to couple the gear mesh dynamic with system dynamics. The transfer matrix method tmm which has been widely applied to structural mechanics, rotor dynamics, and ms dynamics, has such characteristics as easy programming, low matrix order, fast calculation and nonindispensable global dynamics equations. Effect of bearing housings on centrifugal pump rotordynamics. Flapwise vibration computations of coupled helicopter rotorfuselage. Dynamics r4 is a new program system of alfatranzit co. Forstab forstab uses the nite element method to perform lateral forced response analysis and stability analysis. Rotor dynamics wiley eastern limited, new age international.
A disk with a known mass unbalance is placed in the middle. The warranty period is one year where the customer receives full services related to the hotline, bug corrections support, etc. Introduction this software is a set of scripts written in matlab to accompany the above book. Huang transfer matrix method to vibration analysis of rotors with coupler offsets 99 fig. Natural vibration characteristics are solved with different transfer matrix models, and are compared with that gotten by finite element method. A rotor system is modeled as a massless, elastic shaft supported by two nonflexible bearings.
A modified transfer matrix method for the coupling lateral and. This has proven to be insufficient for the analysis of the gas turbinegenerator systems including casing and foundation effects to compute stability and predicted unbalance response. It uses the transfer matrix method and is capable of nding the freefree modes. In this paper, an efficient method of dynamics modeling and vibration control design of a linear hybrid multibody system ms is studied based on the transfer matrix method. It is commonly used to analyze the behavior of structures ranging from jet engines and steam turbines to auto engines and computer disk storage. Since 1994, rma has been helping engineers model and analyze rotating equipment quickly, efficiently, and reliably. Lees cambridge university press, 2010 rotordynamics software manual 1. The responses of a rotor system composed of flexible shafts, unbalanced disks, elastic supports and shafts coupler with misalignment were then investigated. This is for example relevant for the design of antireflective coatings and dielectric mirrors the reflection of light from a single interface between two media is described by the fresnel equations. The rotor blade dynamics program is part of the joint armynavy rotorcraft analysis and design janrad program which was developed to aid in the preliminary design and analysis of helicopter rotor performance, stability. The rotor system is rotating with a constant rotational speed, see figure 2 figure 2 a jeffcott. Mathuria, graduate student, indian institute of technology, bombay.
The calculation of the stiffness nm of pump annular seals c is performed in accordance. Dynamic analysis of geared rotors by finite elements. There are several numerical problems with the transfer matrix method that precludes its use for accurate computations of rotor dynamic behavior of large turbine generators. Back in the 70s, when i was researching the dynamics of the 1150 mw nuclear turbinegenerator with 11 bearings, my advanced transfermatrixbased criticalspeed program missed modes. A customer can buy any set of modules of dynamics r4 program system a package designed for necessary type of analysis.
The application of transfer matrix method tmm ranges from linearnonlinear vibration, composite structure, and multibody system to calculating static deformation, natural vibration, dynamical response, and damage identification. Transfer matrix method is commonly employed for rotor dynamics analysis and is one of the accurate analytical methods. Critical speeds or whirling frequency conditions are computed using transfer matrix method and then the results were compared using finite element method. A quantitative comparison is made between the finite element method and four variants of the transfer matrix method, as applied to free vibration analysis of rotor systems. Pdf in this paper a general transfer matrix method tmm for rotors. Lund has also expanded the transfer matrix analysis to handle multiple, interconnected rotors.
Dynamic analysis of rotating systems and applications. Rotordynamics project gutenberg selfpublishing ebooks. In one of the early examples of the finite element method, nelson and mcvaugh 1976 used a rayleigh beam finite element including the effects of the. It evolved out of lectures delivered at different universities over the last two decades. Transfer matrix method to vibration analysis of rotors. Dynamics of a motorized spindle supported on water. Research on unbalance response characteristics of gas. Transfer matrix in this chapter we introduce and discuss a mathematical method for the analysis of the wave propagation in onedimensional systems. A modified myklestadprohl method for rotating beams has been coded to assist in preliminary helicopter rotor blade design. The transfer matrix method breaks down with multiple bearings and supports. It differs from ordinary methods in multibody system dynamics with respect to the feature that there is no need for a.
The method uses the transfer matrix and is commonly known as the transfer matrix method 7,29. It is different from structural vibration analysis because of the gyroscopic moments. Browse through a list of free utilities, drivers, software, and links to topicrelated sites. Rotor dynamics plays an important role in many engineering fields, such as gas turbine. Since the equation of motion is established referring to. Using the damped critical speed computer program men tioned above, modified to include the trunnion transfer matrix, an analytical study is being performed to. He is currently involved in the design, testing, modification, and installation of rotating equipment. Dyrobes demonstration of melvin prohls paper, 2018. A new version of transfer matrix method for multibody. The dynamics r4 program system is designed for solution of a broad spectrum of multishaft rotor dynamical problems in linear and nonlinear statement. Why is the transfer matrix method no longer the industry standard.
A modified transfer matrix method considering both of the translational and tilting dynamic coefficients of the bearings is established. They are developed by bucher 27, genta 28 and friswell et al. One is the widely used finite element method fem, and the other. Rajiv tiwari,department of mechanical engineering,iit guwahati.
The calculation of rotor free vibration is performed by the method of initial parameters in a matrix form 46. The primary purpose of the software is to illustrate features of rotating machines described in the. A transfer matrix for shafts coupler with parallel misalignment offset was derived. The resulting model and simulation results exhibited. When calculating the rotor dynamics of systems with hydrodynamic bearings, the nonlinear fluid film forces are reduced to linearize stiffness and damping coefficients. Through the derivation, the boundary shears induced by a rotating shaft were first discovered to be coupled in two perpendicular directions. Importance of rotor dynamic analysis, historical overview, objectives of rotor dynamics analysis, summary and scope of the present book. The rotorbearing system is modeled in exactly the same manner as for the usual transfer matrix program 5.
The transfer matrix method tmm was developed for a long time and used widely in structure mechanics and rotor dynamics of the linear. The effects of eccentric factors are discussed on unbalanced vibration. The purpose of this paper is to investigate the dynamic performances of a motorized spindle supported on waterlubricated bearings. In order to avoid the global dynamics equations and increase the computational efficiency for multibody system dynamics msd, the transfer matrix method of multibody system mstmm has been developed and applied very widely in research and engineering in recent 20 years. The rotor is represented by concentrated masses connected by massless shafts figure 1, bearings and foundations are modeled as forces acting oil the masses at the appropriate axial locations. Army on rotor dynamics and bearing design for turboshaft engines used in helicopters. Transfer matrix for rotor coupler with parallel misalignment. Malcolm leader is a turbomachinery consultant and owner of applied machinery dynamics in dickinson, texas. The first of these sections is, in the general case, where the crosssectional moment of inertia and area vary continually in the axial direction. Dynamic analysis of flexible rotor based on transfer symplectic. Rotating shafts this type of a rotating structure can be analyzed using two cases the symmetric case and the unsymmetric case. He spends time doing theoretical design audits and working in the field implementing changes and overseeing installations.