Elastohydrodynamically lubricated finite line contact with couple stress fluids

• Finite EHL line contact analysis is able to portray the edge effect in rollers.
• Use of Couple stress fluid is helpful in increasing contact fluid film thickness.
• Empirical formulae for finite line contact with couple stress fluid are proposed.

The effect of couple stress fluid on the elastohydrodynamically lubricated finite line contact is studied. Modified Reynolds equation is derived from Stokes microcontinuum theory and solved numerically using finite difference method. Owing to the finite contact analysis, the effect of couple stress fluid at the edges of the roller is examined. The study reveals that overall film thickness increases significantly with couple stress parameter. This suggests less wear as there may be a chance of getting direct metal-to-metal contact. The coefficient of friction, which is of greater importance in lubrication, also decreases with increase in the couple-stress parameter. Based on the numerically evaluated results, empirical formulae for central and central minimum film thickness are developed.