Adiabatic analysis of finite width journal bearings with non-newtonian lubricants

This paper presents adiabatic solutions for a finite width hydrodynamic journal bearing with non-newtonian lubricants, obeying the power-law model. The oil film viscosity is also taken to be a function of temperature according to an exponential law. The performance characteristics are obtained for various values of the non-newtonian power-law index n, in the range 0.7-1.2, for the eccentricity ratios e, in the range 0.2-0.8, for the slenderness ratios 0.5, 1.0 and 2.0, and for the rotational speeds 1000, 1500 and 2000 rev min^-1. Numerical results indicate that for the shear thickening fluids (n > 1), the load-carrying capacity, maximum temperature and frictional force may be greatly increased, while for the pseudoplastic fluids (n > 1), they all decrease. The adiabatic solutions also show that the load-carrying capacity may be greatly reduced to one-third of its value when compared with that given by the isothermal solutions. In addition, thermal effects are found to be more pronounced at higher values of the flow behaviour index n, eccentricity and rotational speed.