Both theoretical and experimental thermohydrodynamic problem of a finite length journal bearing is studied. The analysis takes into acount heat transfer between the film and both the shaft and the bush. Cavitation and lubricant recirculation are also taken into account. The experimental program is conducted on an original device to study the performance of a plain bearing. The pressure and the temperature distribution on bearing wall are measured along with the eccentricity ratio and the flows rate for different speeds and loads. The effect on the eccentricity ratio of differential dilatation is underlined. Agreement between theoretical results and experimental data is satisfactory.

The present work deals with the analysis of the incompressible laminar shear driven flow in a channel of which one of the walls carries a macro roughness pattern while the opposite one has a parallel velocity. The problem is discussed from the standpoint of lubrication theory and it is shown that the usual simplified models as the Reynolds or the Stokes equations are not applicable. Numerical results are presented for three types of two dimensional macro-roughness and two versions of a three dimensional one. It is shown that a pressure generation effect occurs with increasing the relative importance of convective inertia. Previous analyses found in the literature discussed only the increase of the shear stress due to the presence of the macro roughness but the lift effect due to the pressure generation has never been enlightened up to now. It is further discussed that, extrapolated to a very large number of macro roughness characterizing a textured surface, this new effect could be added to the other lift generating mechanisms of the lubrication theory. It could thus bring a different light on inertia effects stemming from the use of textured surfaces.

A general THD theory and a comparison between theoretical and experimental results are presented. The generalized Reynolds equation, the energy equation in the film, and the heat transfer equation in the bush and the shaft are solved simultaneously. The cavitation in the film, the lubricant recirculation, and the reversed flow at the inlet are taken into account. In addition, the thermoelastic deformations are also calculated in order to define the film thickness. Good agreement is found between experimental data and theoretical results which include thermoelastic displacements of both the shaft and the bush.

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Operating characteristics of four-shoe tilting-pad journal bearings of 100 mm diameter and 70 mm length are determined on an experimental device. The load, between pad configuration, varies from 0 to 10,000 N and the rotational speed is up to 4000 rpm. Forty thermocouples are used in order to measure bearing element temperatures (babbitt, shaft, housing and oil baths). The influence of operating conditions and preload ratio on bearing performances are studied. Comparison between theoretical and experimental results is presented. The theoretical model is also performed on a large tilting-pad journal bearing which was investigated experimentally by other authors.