Mathematical modeling of journal bearing lubricated with non-newtonian fluid

Abstract

In this work it has been theoretically studied the influence of the nonNewtonian fluids on the lubricated hydrodynamic journal bearings. For this purpose, a FORTRAN program was developed to resolve the two-dimensional Reynolds equation in polar coordinates. Hence, a finite difference method was used. Initially, dynamic viscosity values are determined for the different nonNewtonian lubricants using Walther equation model. The journal bearing behavior has been simulated according to the eccentricity ratio, the L/Ds ratio and the rheological characteristic index in case of industrial lubricating oils in accordance with ISO 3448 standard especially ISO-VG32, ISO-VG46 and ISOVG68. The simulation has allowed performing analysis of journal bearing performances according to pressure, bearing load capacity and oil flow rate. The study concludes that the hydrodynamic characteristics of the journal bearing are influenced by the type of lubricant, eccentricity ratio and the L/ D ratio.