Modeling the Viscoelastic Effects in the Hydrodynamic Lubrication of Journal Bearing in a High-Torque Low Speed Diesel Engine Available to Purchase

Multi-grade diesel lubricants exhibit viscoelastic characteristics, which affect journal bearing lubrication of a high torque engine at a low speed. During engine operation the main end of the crankshaft journal is most vulnerable to the cyclic combustion loads and must be protected against adhesive wear. This research models the Newtonian behavior of a lubricant by solving the 2-D Reynolds equation and determining the film thickness between the bearing and the crankshaft. It is followed by solving the continuity and Navier-Stokes equations to ensure conservation of mass and momentum of the lubricant flows. The constitutive equations exhibiting viscoelastic characteristics are coupled with the momentum conservation equations to generate simulation results for non-Newtonian lubricant response. The steady state wedging and transient squeeze effects are studied for a viscoelastic engine lubricant at low speed. The simulation results for Newtonian and viscoelastic engine lubricants are analyzed separately and then compared for definite conclusions. The results show that at a low initial speed the Newtonian lubricant is not affective against the cyclic loads to prevent physical contact and wear of interacting surfaces. The viscoelastic characteristics of the lubricant visibly contribute towards improving the pressure and film thickness profiles of a high-torque low-speed engine. It reduces the chances of breakdown of lubricant film and enhances the life of crankshaft by preventing adhesive wear.