Influence of roughness on the behavior of three-dimensional journal bearing based on fluid-structure interaction approach

In present study, a fluid-structure interaction (FSI) approach is proposed for predicting the effects of roughness on the performance of hydrodynamically lubricated three-dimensional (3D) journal bearing, taking mechanical deformation effects. The multi-phase cavitation mass flow conservation model is adopted, in which the phase change boundary condition is allowable. The results show that the mechanical deformation effect on bearing performance has been confirmed to be substantial. When the deformation of the structure is considered in calculating the change of film thickness, the bearings carry less load (i.e. 30-70 % smaller depending on the surface roughness value) as compared to the case in which the deformation is neglected. It is also highlighted that the hydrodynamic pressure and load support decrease with surface roughness.