The influence of pole piece geometry on the lifespan of the stationary magnetic fluid seal

Authors

  • Sofiya G. Sharyna Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus
  • Mikhail S. Krakov Belarusian National Technical University, 65 Niezaliezhnasci Avenue, Minsk 220013, Belarus

Keywords:

diffusion, magnetophoresis, magnetic fluid, numerical methods, computer simulation
Supporting Agencies
The study was carried out within the framework of the research work «Dynamics of heat and mass transfer processes in colloids of magnetic nanoparticles» (state programme of scientific research «Energy and nuclear processes and technologies», subprogramme «Energy processes and technologies», assignment 2.21 «Development of the theory of mass transfer in colloids and suspensions to determine the modes of magnetorheological processing, ensuring the radiation resistance of elements of powerful laser systems»).

Abstract

The paper presents the results of a numerical simulation of the problem of changing the concentration of magnetic particles over time in a magnetic fluid seal (MFS) operating in the standby mode. It is noted that the process of reconcentration is determined by the balance of magnetophoresis and concentration diffusion. The study was performed for the two most common pole piece geometries – triangular and rectangular. The governing equations take into account the diffusion coefficient’s dependence on the concentration of magnetic particles and a modified expression for the mobility of magnetic particles. A comparison of the influence of pole piece geometry on the MFS lifespan was carried out. Under the influence of a high-gradient magnetic field in the MFS, magnetic particles tend to the region of higher magnetic field strength. As a result, the concentration of magnetic particles in the gap of the MFS increases significantly, which leads to an increase the viscosity of the magnetic fluid. Excessive increase in the viscosity of the magnetic fluid may result in the shaft not being able to rotate, i. e., seal failure. The lifespan of the MFS is considered to be the time during which the magnetic fluid in the gap of the MFS loses its fluidity. It was determined that the lifespan of the MFS with a triangular pole piece geometry exceeds the lifespan of the MFS with a rectangular pole piece geometry. When using vacuum oil as the base fluid, the failure-free operation time of the MFS, depending on its parameters, can range from a month to several years.

Author Biographies

  • Sofiya G. Sharyna, Belarusian State University, 4 Niezaliezhnasci Avenue, Minsk 220030, Belarus

    assistant at the department of computer modelling, faculty of physics

  • Mikhail S. Krakov, Belarusian National Technical University, 65 Niezaliezhnasci Avenue, Minsk 220013, Belarus

    doctor of science (physics and mathematics), full professor; professor at the department of computer modelling, faculty of physics, Belarusian State University, and professor at the UNESCO department «Energy saving and renewable energy sources», faculty of management technologies and humanities, Belarusian National Technical University

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Published

2025-11-03 — Updated on 2025-11-03

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No. 2 (2025): Journal of the Belarusian State University. Physics

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Research Instruments and Methods

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How to Cite

(1)
Sharyna, S. G.; Krakov, M. S. The Influence of Pole Piece Geometry on the Lifespan of the Stationary Magnetic Fluid Seal. Журнал Белорусского государственного университета. Физика 2025, No. 2, 19-30.