EFFECTS OF COUPLE-STRESSES ON THE LUBRICATION OF FINITE JOURNAL BEARINGS

Based on the microcontinuum theory, this paper investigates theoretica lly the rheological effects of couple stress fluids on the lubrication performance of finite journal bearings. To take into account the coup le stress effects resulting from lubricant blended with additives, the modified Reynolds equation is derived from the Stokes constitutive eq uations. With zero pressure-gradient conditions for the film extent, t he film pressure is solved numerically using the conjugate gradient me thod of iteration. Various bearing characteristics are then calculated . According to the results predicted, the presence of couple stresses has a significant affect on the static characteristics of finite journ al bearings. Compared with the Newtonian-lubricant case, the effects o f couple stresses enhance the load-carrying capacity, as well as reduc e the friction parameter and the attitude angle. Overall, the couple s tress effects improve the lubrication characteristics of the journal-b earing system. These results agree qualitatively with experimental wor ks. (C) 1997 Elsevier Science S.A.