Rotor-to-stator, rub-related, thermal/mechanical effects in rotating machinery

Goldman, Paul; Muszynska, A.

doi:10.1016/0960-0779(94)00165-m

Cited by 39 publications

(24 citation statements)

References 12 publications

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“…Hence it is desirable to reduce the clearance by as much as possible. Unfortunately, it cannot be reduced below a certain minimum level due to uncertainties in the dynamics, fluid dynamics Bently, 1996, Ehrich, 1993), thermal loads (Goldman and Muszynska, 1995), machining tolerances and material properties (Maozhong, et al, 2002, Marscher, 1980. The more accurately these parameters are known, the smaller the clearance that can be made.…”

Section: Introductionmentioning

confidence: 99%

Contact analysis of a flexible bladed-rotor

Lesaffre

Sinou

Thouverez

2007

European Journal of Mechanics - A/Solids

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This paper presents a model of fully flexible bladed rotor developed in the rotating frame. An energetic method is used to obtain the matrix equations of the dynamic behaviour of the system. The gyroscopic effects as well as the spin softening effects and the centrifugal stiffening effects, taken into account through a pre-stressed potential, are included in the model. In the rotating frame, the eigenvalues' imaginary parts of the latter matrix equation give the Campbell diagram of the system and its stability can be analysed through its associated eigenvalues' real parts. The turbo machine casing is also modelled by an elastic ring in the rotating frame through an energetic method. Thus, the contact problem between the rotor and the stator can be treated as a static problem. Prior to the study of the complete problem of contact between the flexible blades of the rotor and the flexible casing, a simple model of an elastic ring having only one mode shape, excited by rotating loads is developed in the rotating frame too, in order to underline divergence instabilities and mode couplings. Then, the real complex problem of contact between the blades and the casing, without rubbing, is studied. The stable balanced static contact configurations of the structure are found as function of the rotational speed of the rotor. Finally, the results are compared to these of the simple model of rotating spring-masses on an elastic ring.

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Section: Introductionmentioning

confidence: 99%

Contact analysis of a flexible bladed-rotor

Lesaffre

Sinou

Thouverez

2007

European Journal of Mechanics - A/Solids

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“…In this paper a simulation-driven methodology is used [Bylund 2004;Goldak et al 2007]. Bylund states that one way of reaching simulation-driven design is by providing simulation tools that can be used by the designers themselves.…”

Section: Simulation-driven Design Methodologymentioning

confidence: 99%

“…In addition, the direction of the vibration is important, and forward whirl therefore has to be distinguished from backward whirl [Genta 1999]. Some rotor dynamical systems become strongly nonlinear due to for example clearances [Chu and Zhang 1997;Edwards et al 1999;Ganesan 1996;Goldman and Muszynska 1995;Muszynska and Goldman 1995], processes [Karlberg and Aidanpää 2007], bearings [Harris 1991] etc. Hence, in rotor dynamical software, it is important to enable predictions of linear as well as nonlinear analysis of rotating machinery 4.2.…”

Section: Simulation-driven Rotor Dynamical Designmentioning

confidence: 99%

Mechanics of materials and structures: a simulation-driven design approach

Karlsson

Pahkamaa

Karlberg

et al. 2011

J. Mech. Mater. Struct.

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Engineering product development has developed considerably over the past decade. In order for industry to keep up with continuously changing requirements, it is necessary to develop new and innovative simulation methods. However, few tools and methods for simulation-driven design have been applied in industrial settings and proven to actually drive the development and selection of the ideal solution. Such tools, based on fundamental equations, are the focus of this paper.In this paper the work is based on two cases of mechanics of materials and structures: welding and rotor dynamical simulations. These two examples of simulation-driven design indicate that a larger design space can be explored and that more possible solutions can be evaluated. Therefore, the approach improves the probability of innovations and finding optimal solutions.A calibrated block dumping approach can be used to increase the efficiency of welding simulations when many simulations are required.

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“…Hence it is desirable to reduce the clearance by as much as possible. It cannot be reduced below a certain minimum level due to uncertainties in the dynamics, fluid dynamics [3,4], thermal loads [5], the machining tolerances and material properties [6,7]. The more accurate these parameters are known, the smaller the clearance can be made.…”

Section: Introductionmentioning

confidence: 99%

Stability Analysis of a Flexible Bladed-Rotor

Lesaffre

Sinou

Thouverez³

2005

KEM

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In any high-performance turbo-machinery, instability prediction and damage are commonly occurring problems. The aim of this paper is to present stability analysis of a fully-bladed flexible rotor. The flexural vibrations of the blades as well as those of the shaft are considered; the energetic approach used includes the effect of the rotational inertia. Then stability detection, bringing loci veering phenomena and coalescence, in case of asymmetric rotor, to the fore, is made in order to determine a parametric domain where turbomachinery cannot encounter damages. Moreover, extensive parametric studies including for instance the length and the stagger angle of the blades are presented in order to obtain robust criterion for stable and unstable areas prediction. Finally, the rotor/stator contact is introduced and the effect of the radial load acting on the blades when rubbing against a carter is considered. IntroductionThe basic objective of turbo-machinery designers is to increase the efficiency of their machine. The efficiencies of both turbo-generators and jet engines depend strongly on the clearance between the rotating and the stationary parts [1,2]: the wider the clearance, the less efficient the machine. Hence it is desirable to reduce the clearance by as much as possible. It cannot be reduced below a certain minimum level due to uncertainties in the dynamics, fluid dynamics [3,4], thermal loads [5], the machining tolerances and material properties [6,7]. The more accurate these parameters are known, the smaller the clearance can be made. However, reduced clearances increase the possibility of violent contacts between rotor and stator and under certain operating conditions, including the dynamic properties of the rotor and the stator and the speed of rotation, the contacts may continue and drive the rotor-stator system unstable [8,9,10]. A common interest of the rotating-machinery industry is to better understand the dynamic behaviour of rotating structures and in particular that of flexible bladed-rotor whose dynamic behaviour differs from those usually studied in rotor-dynamics. Thus, the instability of

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Rotor-to-stator, rub-related, thermal/mechanical effects in rotating machinery

Cited by 39 publications

References 12 publications

Contact analysis of a flexible bladed-rotor

Contact analysis of a flexible bladed-rotor

Mechanics of materials and structures: a simulation-driven design approach

Stability Analysis of a Flexible Bladed-Rotor

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