Thermohydrodynamic analysis of journal bearings lubricated with couple stress fluids

Thermohydrodynamic analysis of journal bearings is extended to include coup le stress effects in lubricants blended with high polymer additives. Based on the micro-continuum theory, a modified energy equation is derived and th en is simultaneously solved with the heat transfer equation as well as the modified Reynolds equation. The effects of couple stress on the key perform ance of a finite journal bearing, such as maximum temperature, shaft temper ature, load capacity, friction force, friction coefficient, and side leakag e flow, are presented. The results have shown that lubricants with couple s tresses, compared with Newtonian lubricants, not only yield an obvious incr ease in load capacity and decrease in friction coefficient, but also produc e a lower bearing temperature field. Thus it can be concluded that the lubr icant with couple stress does improve the performance of journal bearings. (C) 2001 Elsevier Science Ltd. All rights reserved.