The friction force and friction coefficient in the journal sliding bearing ferrofluid lubricated with different concentrations of magnetic particles

• Autorzy: Frycz M. , Miszczak A.
• Języki publikacji: EN

Abstrakty

EN

There is an important operational parameter in the case of sliding bearings are friction forces and coefficient of friction. It depends on how much proportions of heat in the gap of the oil film from the value of the friction force. Ferrofluid lubricated sliding bearings have specific structure and are suitable only for use in specific cases. We may use them in the absence of gravity, vacuum, or in case of strong magnetic fields or radioactive. Maintenance of lubricant in the oil-gap as well as the viscosity change occurs through controlling of the external magnetic field. Change of the value of viscosity and mass forces (magnetic forces) in the equation of momentum depends on the concentration of magnetic particles and the intensity of external magnetic field. The aim of this paper is to present the influence of concentration of magnetic particles on the friction force value and coefficient of friction. The numerical calculations of friction forces and friction coefficient have been performed before setting the hydrodynamic pressure and a lift force from the Reynolds-type equation. Reynolds-type equation has been derived from basic equations, ie equations of momentum and equations of stream's continuity. There have been also used Maxwell's equations for the ferrofluid in the case of stationary magnetic field's existence. It has been assumed stationary and laminar flow of lubricant liquid and the isothermal model for lubrication of slide bearings. As the constitutive equation has been used Rivlin-Ericksen one. The cylindrical journal bearing of finite length with the smooth sleeve of whole angle of a belt has been taken into consideration. In a thin layer of oil film has been assumed constancy of the oil density with temperature changes and the independence of the oil's thermal conductivity coefficient from thermal changes. The viscosity of the oil depends mainly on the magnetic field.

Słowa kluczowe

EN

hydrodynamic pressure; capacity; friction force; friction coefficient; ferrofluid; numeric calculation

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2011
• Tom: Vol. 18, No. 4
• Strony: 113--120
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Frycz M.

autor

Miszczak A.

• Gdynia Maritime University, Faculty of Marine Engineering Morska Street 83, PL 81 225 Gdynia, Poland tel.: [phone], fax: [phone],

Bibliografia

• [1] Böhme, G., Strömungsmechanik nicht-Newtonscher Fluide, Teubner Studienbücher Mechanik, Stuttgart 1981.
• [2] Lang, O. R., Steinhilper, W., Gleitlager, Springer Verlag, Berlin-Heidelberg-New York 1978.
• [3] Miszczak, A., Analiza hydrodynamicznego smarowania ferrocieczą poprzecznych łożysk ślizgowych, Monografia, Fundacja Rozwoju Akademii Morskiej, Gdynia 2006.
• [4] Miszczak, A., A modelling of magnetic field in journal bearing gap, Tribologia, 5 (185), pp. 1503-1512, 2002.
• [5] Walicka, A., Inertia Effect on the Pressure Distribution in a Thrust Bearing Lubricated by Conducting and Magnetic Viscoelastic Fluids, International Journal of Applied Mechanics and Engineering, Vol. 7, pp. 99-108, 2002.
• [6] Wierzcholski, K., Mathematical Theory of Lubrication, Politechnika Szczecińska, Szczecin 1992.
• [7] Wierzcholski, K., Teoria niekonwencjonalnego smarowania łożysk ślizgowych, Prace Naukowe Politechniki Szczecińskiej, Nr 527, Szczecin 1995.
• [8] Wierzcholski, K., Wissussek, D., Presentation of Some Simplifications for hydrodynamic flow of Rivlin Ericksen Lubricant, Tribologia, 6 (144), pp. 653-663, 1995.