Compulsator rotordynamics and suspension design

Murphy, Brian T.; Manifold, S.M.; Kitzmiller, J.R.

doi:10.1109/20.560058

Cited by 11 publications

(7 citation statements)

References 6 publications

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“…Zeidan (1995) discusses successful applications of ISFDs in the petrochemical industry. Murphy, et al (1996) perform imbalance tests in a compulsator rotor supported on integral dampers with L shaped EDM springs. The test rotor-ISFDs response is well damped, linear and without jumps, although critical speeds relocate due to the differences in theoretical and measured structural stiffnesses.…”

Section: Presented At the International Gas Turbine And Aeroengine Congmentioning

confidence: 99%

“…The transient response is detected with a piezoelectric accelerometer (26.1 gr) installed through a magnetic base at different locations along the rotor. Table 1 presents a summary of the test natural frequencies along with predictions based on a 38 station -transfer matrix model using a commercial program (Murphy, 1995). The coupling in the rotor causes a sharp reduction of the first natural frequency since this is located at an anti-node for the first elastic mode of vibration.…”

Section: Identification Of Rotor Free -Free Modal Frequenciesmentioning

confidence: 99%

See 1 more Smart Citation

Imbalance Response of a Rotor Supported on Open-Ends Integral Squeeze Film Dampers

Santiago

Andrés

Oliveras

1998

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation;

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Rotor vibration attenuation and structural components isolation in jet engines are achieved with squeeze film dampers, many of them supported on long elastic squirrel cages. Integral squeeze film dampers (ISFDs) are comprised of arcuate pads and wire-EDM webs rendering a compact viscoelastic support. An experimental study is conducted to evaluate the effectiveness of ISFDs in attenuating the imbalance response of a massive test rotor. Measurements of the damper structural stiffness and rotor natural frequencies are detailed. Impact tests on the test rotor supported on its dampers reveal the supporting structure to be very flexible, thus requiring the experimental evaluation of an equivalent stiffness for the damper and supports system. System damping coefficients extracted from impact load excitations vary with the lubricant viscosity and include a significant structural damping from the bearing supports. Rotor coast-down tests demonstrate the ISFDs to damp well the rotor response with peak vibration amplitude proportional (linear) to the imbalance. Viscous damping coefficients estimated from the amplitude response at the critical speeds agree reasonably well with predictions from a full-film, finite element model.

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Section: Presented At the International Gas Turbine And Aeroengine Congmentioning

confidence: 99%

Section: Identification Of Rotor Free -Free Modal Frequenciesmentioning

confidence: 99%

Imbalance Response of a Rotor Supported on Open-Ends Integral Squeeze Film Dampers

Santiago

Andrés

Oliveras

1998

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation;

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“…Obtaining an accurate solution of the coupled electromechanical problem, which is governed by unstable poles, is very important because the accurate knowledge of the open-loop evolution is essential for the design of the control system. Several papers [13][14][15][16][17][18][19] highlight the actual need of accurate choices of geometry and configurations, also in the early design process of MAGLEV devices.…”

Section: Introductionmentioning

confidence: 99%

A new predictor–corrector approach for the numerical integration of coupled electromechanical equations

Tripodi

Musolino

Rizzo

et al. 2015

Numerical Meth Engineering

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Summary In this paper, a new approach for the numerical solution of coupled electromechanical problems is presented. The structure of the considered problem consists of the low‐frequency integral formulation of the Maxwell equations coupled with Newton–Euler rigid‐body dynamic equations. Two different integration schemes based on the predictor–corrector approach are presented and discussed. In the first method, the electrical equation is integrated with an implicit single‐step time marching algorithm, while the mechanical dynamics is studied by a predictor–corrector scheme. The predictor uses the forward Euler method, while the corrector is based on the trapezoidal rule. The second method is based on the use of two interleaved predictor–corrector schemes: one for the electrical equations and the other for the mechanical ones. Both the presented methods have been validated by comparison with experimental data (when available) and with results obtained by other numerical formulations; in problems characterized by low speeds, both schemes produce accurate results, with similar computation times. When high speeds are involved, the first scheme needs shorter time steps (i.e., longer computation times) in order to achieve the same accuracy of the second one. A brief discussion on extending the algorithm for simulating deformable bodies is also presented. An example of application to a two‐degree‐of‐freedom levitating device based on permanent magnets is finally reported. Copyright © 2015 John Wiley & Sons, Ltd.

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“…In fluid journal bearings value of the ratio α is near 0.5 [127,130,131,[133][134][135] and the rotation becomes unstable at the speed which is approximately twice of the first critical speed. Subsynchronous rotor vibrations that exist due to subsynchronous spinning of the damper become unstable when their frequency reaches critical frequency.…”

Section: Jeffcott Rotor With Non-synchronous Dampingmentioning

confidence: 99%

“…Sources of rotating damping [83,126] in electrical machines in general are eddy-currents [87], press fits, material damping, interaction with fluids [134] etc. Moreover, flexural modes are often poorly damped externally -bearings are located at the ends of the rotor and/or have insufficient bandwidth to cope with those vibrations.…”

Section: Stability Of the Jeffcott Rotor With Dampingmentioning

confidence: 99%

Limits, Modeling and Design of High-Speed Permanent Magnet Machines

Borisavljevic¹

2013

Springer Theses

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Compulsator rotordynamics and suspension design

Cited by 11 publications

References 6 publications

Imbalance Response of a Rotor Supported on Open-Ends Integral Squeeze Film Dampers

Imbalance Response of a Rotor Supported on Open-Ends Integral Squeeze Film Dampers

A new predictor–corrector approach for the numerical integration of coupled electromechanical equations

Limits, Modeling and Design of High-Speed Permanent Magnet Machines

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