ALGORYTHM FOR VARIABLE PSEUDOVISCOSITY COEFFICIENTS UNDER AN EXPERIMENTAL BASIS
Journal Title: Tribologia - Year 2013, Vol 250, Issue 4
Abstract
Constitutive equations between stresses and deformations for oils with pseudo-viscosity properties are usually described by the Rivlin-Ericksen relations. In these relations two pseudo-viscosity coefficients occur. Up to now, in numerous scientific papers concerning the journal bearing lubrication with visco-elastic oils, the mentioned pseudo-viscosity coefficients have been treated as constant values. By virtue of performed measurements, it is evident that experimental curves describing visco-elastic oil dynamic viscosity versus shear rate had shapes that cannot be obtained for the constant pseudo-viscosity coefficients. In this case, only possible are the unknown dependences between oil dynamic viscosity and share rate. This paper shows the algorithm derivation for variable pseudo- -viscosity coefficients as a function of shear rate using pseudo-viscosity oils and taking into account the experimental data obtained from viscosity measurements.
Authors and Affiliations
Krzysztof Wierzcholski, Andrzej Miszczak
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