Thermo-hydrodynamic Analysis of Multistep Journal Bearing using Computational Fluid Dynamics Simulation

Journal bearing is a machine element that is used to maintain the continuous rotation of the shaft on its axis. The rising demand for efficient and economical journal bearing applications has resulted in increased demand for high-speed machines. An increase in engine speed raises the distribution of pressure, temperature, and vapor volume fraction. Most of the research still only focuses on increasing pressure distribution and load-carrying capacity. However, the value of friction force, temperature distribution, and vapor volume fraction must also be considered such that the lubrication of the journal bearing is close to the real situation. Therefore, the research was conducted by varying the geometry modelling through multistep textures using viscous boundaries and thermo-hydrodynamic lubrication. Owing to the high load and speed usage on multistep journal bearings, research on the effect of eccentricity ratio and inlet and outlet temperatures on the tribological performance of multistep journal bearings was conducted. The analysis has been performed using a multistep journal bearing modelling 3D computational fluid dynamics considering the effect of cavitation on temperature. The results of this study indicate that the use of multistep textures on journal bearings can reduce friction force, temperature, and vapor volume fraction. The variation of the eccentricity ratio shows that a high eccentricity ratio leads to a high three parameters (i.e., friction force, temperature, and vapor volume fraction). Finally, for variations of inlet and outlet temperatures, such parameters are high when the inlet and outlet temperatures are high.