Determination of pseudo-viscosity coefficients for visco-elastic lubricants

• Autorzy: Wierzcholski K.
• Języki publikacji: EN

Abstrakty

EN

In this paper we assume determination of pseudo-viscosity coefficients of visco-elastic non-Newtonian fluid flow directly near the cooperating micro-bearing surface. We show the constitutive stress-strain dependencies of non-Newtonian visco-elastic media with regard to the content of addition of nano-particles. The greater content of nano-particles and influences of superficial layer of cooperating surfaces on the dynamic oil viscosity, the more distinct non-Newtonian properties. The non-Newtonian properties create non-linear dependencies between strain and stress. Moreover the dynamic viscosity or apparent dynamic viscosity of oil often decreases along with shear rate increasing during motion. dynamic viscosity of oil inside very thin boundary layers depends on Young's modulus of the cell body being in contact with the oil. Considered visco-elastic oils with nano-particles have non-Newtonian pseudo-plastic properties, described in the beginning by means of Rivlin-Ericksen constitutive relations. Hence their stress-strain dependencies presented in this paper have the modified Rivlin-Ericksen form. Scientific efforts brought into this elaboration represent an impact to the considered domain by providing for some data on comparisons between boundary conditions for lubrication flow in super thin boundary layer lying on the external surface of biological cells of joint cartilage and boundary conditions for lubrication of micro-bearing of shaft diameter smaller than 2 mm.

Słowa kluczowe

EN

pseudo elastic coefficients; method of determination

• 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: 2010
• Tom: Vol. 17, No. 2
• Strony: 491--496
• Opis fizyczny: Bibliogr. 7 poz., rys.

Twórcy

autor

Wierzcholski K.

• Technical University of Koszalin Institute of Mechatronics, Nanotechnology and Vacuum Technique Racławicka Street 15-17, 75-620 Koszalin, Poland tel: [phone], fax: [phone],

Bibliografia

• [1] Huang, C.-Y., Soltz, M. A., Kopacz, M., Mow, V. C., Ateshian, G. A., Experimental Verification of the Roles of Intrinsic Matrix Viscoelasticity and Tension-Compression Nonlinearity in the Biphasic Response of Cartilage, Trans. of ASME, Vol. 125, pp. 84-93, 2003.
• [2] Fung, Y. C., The Meaning of Constitutive Equations in Biomechanics, Mechanical Properties of Living Tissues, Springer Verlag, Berlin 1993.
• [3] Łukaszewicz, G., Micropolar Fluids Theory and Application, Birkhauser, Berlin 1999.
• [4] Truckenbrodt, E., Strömungsmechanik, Springer Verlag, New York, Berlin 1986.
• [5] Truesdell, C., A First Course in Rational Continuum Mechanics John, Baltimore, Maryland, Hopkins University 1972.
• [6] Wierzcholski, K., Pytko, S., Analytical Biobearing Lubrication for Experimental Dependencies Between Shear Rate and Synovial Fluid Viscosity, Proceedings of International Tribology Conference in Yokohama, Vol. 3, pp. 1975-1980, Yokohama 1995.
• [7] Wierzcholski, K., The Physical Dependences of Synovial Fluid (in Polish), Mechanics in Medicine, Vol. 6, Proceedings of Scientific Seminar, pp. 185-189, Rzeszów 2002.