General Approach to Modeling of Non-Contact Seals and Their Effect on the Dynamics of a Centrifugal Machine Rotor

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DOI https://doi.org/10.15407/pmach2022.01.032
Journal Journal of Mechanical Engineering – Problemy Mashynobuduvannia
Publisher A. Pidhornyi Institute for Mechanical Engineering Problems
National Academy of Science of Ukraine
ISSN  2709-2984 (Print), 2709-2992 (Online)
Issue Vol. 25, no. 1, 2022 (March)
Pages 32-39
Cited by J. of Mech. Eng., 2022, vol. 25, no. 1, pp. 32-39

 

Author

Serhii S. Shevchenko, Pukhov Institute for Modelling in Energy Engineering of NASU (15, Heneral Naumov str., Kyiv, 03164, Ukraine), e-mail: shevchenkoss@nas.gov.ua, ORCID: 0000-0002-5425-9259

 

Abstract

There is a constant demand for higher equipment parameters, such as pressure of a sealing medium and shaft rotation speed. However, as the parameters rise it becomes more difficult to ensure hermetization efficiency. Moreover, sealing systems affect the overall operational safety of the equipment, especially vibratory. Non-contact seals are considered as hydrostatodynamic supports that can effectively damp rotor oscillations. Models of an impulse and a groove seals, models of rotor-seals system and rotor-auto-unloading system, model of a shaftless pump are studied to evaluate an effect of these sealing systems on oscillatory characteristics of rotor. Analytical dependencies for computation the dynamic characteristics of impulse seals, hydromechanical systems rotor-seals and rotor-auto-unloading, as well as shaftless pumps are obtained. These dependencies describe the radial-angular vibrations of a centrifugal machine rotor in seals-supports. Equations for computation the amplitude-frequency characteristics are given. The directions of improving the оperational safety of critical pumping equipment by purposefully increasing the rigidity of non-contact seals that leads to higher rotor vibration stability have been determined.

 

Keywords: impulse seals, groove seals, auto unloading device, seals-supports, mathematical model, radial-angular vibrations, frequency characteristics.

 

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Received 17 March 2022

Published 30 March 2022