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The paper aims to analyze the evolution of the lubrication regime by studying the variation of friction coefficient with the rotational speed of the shaft and the impact of the applied load in the starting phase of a cylindrical journal bearing. The paper also aims to ensure that the oil layer is large enough for the rough edges of the outer layer of the bushing and the shaft cannot come into contact. The bearing is made of steel backing material and babbitted (88 per cent tin) on its inner surface.

A numerical analysis is performed taking into account the thermal effect to better predict the operating performance of a hydrodynamic plain cylindrical journal bearing during the start-up and observe the variation of the heat production in bushing inner surface. The flow is modeled based on the Reynolds equation and discretized using the finite volume method.

The evolutions of the start-up speeds of the bearing have remarkable influence on friction torque; average temperature and dissipated power increased with increasing speed and increasing load, but the maximum pressure and the eccentricity decreased with the increase of the start-up speed. The friction coefficient, minimum film thickness and attitude angle increase with elevation of start-up speed.

For the start-up speed of 750, 1,000 and 1,800 rpm and an applied load of 1,000 N, the regime of lubrication of the bearing passes the hydrodynamic regime to the mixed regime; therefore, during start-up and under heavy loads, the bearing must move very quickly at these speeds to avoid contact of the inner surface of the bearing and the shaft.

This paper aims to investigate the fluid flow regime and the elastic effect in a plain cylindrical journal bearing subjected to highly severe operating velocity to better predict the behavior of the bearing for the turbulent flow regime.

A numerical analysis of the behavior of an elastohydrodynamic for cylindrical journal bearing finite dimension coated with antifriction material in turbulent regime, is implemented using the code-ANSYS CFX. This analysis is performed by solving the Navier–Stocks equations of continuity by the method of finite volume for rotational speeds ranging from 6,000 to 15,000 rpm, that is to say for different Reynolds number.

This study aims to better predict the elastic behavior in a journal bearing subjected to severe operating conditions. The speed of rotation varies from 6,000 to 15,000 rpm.

The results clearly show that significant pressures are applied in the extreme case of speed, that is to say to the turbulent regime. There is an emergence of new rupture zone pressure, we do not usually see the regime established; the level of the supply groove. Displacement of shaft relative to the bearing is remarkable by introducing the elastic effect and the turbulent regime.