Lubricating performance of dynamically loaded journal bearings based on couple stress fluid model

Most of the lubricants used in practice are couple stress fluids blended with small amounts of high polymer additives. The couple stress model was used to study the lubricating performance for dynamically loaded journal bearings. The modified Reynolds equation of couple stress fluids under dynamic load conditions was derived and then used to calculate the pressure distribution of dynamically loaded journal bearings. The model was also used to analyze the different effects of Newtonian fluids and couple stress fluids on bearing load capacity, journal center orbit and friction coefficient. The results show that longer chain additive molecules increase the effects of the couple stress, the load capacity and the film thickness and reduce the friction coefficient.