Thermo-hydrodynamic behaviour of a thin lubricant film

The thermo-hydrodynamic behaviour of lubricant films strongly depends on the operating conditions (pressure, speed), on the physical properties of the lubricant, on the temperature level and is often nonlinear. The thermo-hydrodynamic study of a thin fluid film between two parallel planes in relative motion is presented in this paper. The case considered is that of not fully-developed thermal conditions and temperature independent physical properties of the lubricant. A 2D analytical solution is proposed to determine the temperature distribution. It is shown that the flow generated by viscous dissipation is completely transmitted to both boundary solids, the fraction transported by the fluid being negligible. The thermal coupling of the two solids can then be represented by a model of contact equivalent to the case of solid friction. The thermal contact resistance is replaced by the thermal resistance of the film.