3rd TAGRA

The purpose of this study was to analyze the three-dimensional stress distribution in a journal bearing using a one-way coupled Computational Fluid Dynamics (CFD) and Fluid–Structure Interaction (FSI) model. Numerical simulations were performed using ANSYS 2023 R2 software. The hydrodynamic pressure distribution was obtained under laminar, isothermal, steady-state conditions at an eccentricity ratio of 0.6, with a radial clearance of 0.04 mm, a journal speed of 1200 rpm, and a lubricant dynamic viscosity of 0.022 Pas at 70 °C. The attitude angle was determined through a two-step approach. First, a preliminary model with vertical eccentricity was simulated, and the load-carrying capacity components (Fx, Fy) were obtained by integrating the pressure over the journal surface. The attitude angle was then calculated from the arctangent of these components, and the geometry was rebuilt accordingly for the FSI analysis. The Gumbel boundary condition was applied in the divergent region. The numerical model was verified against a finite difference solution of the Reynolds equation under the same boundary condition, following the approach used in previous CFD–FSI studies. The resulting pressure field was applied as a load to the inner surface of a ZA-27 journal bearing. The full-field distribution maps of the stress components on the bearing surface, including axial, radial, tangential, maximum shear, and von Mises stresses, were determined. The CFD results revealed a pressure field concentrated in the convergent region, with a parabolic profile in the axial direction reaching a maximum at the mid-plane and decreasing towards the edges. The FSI analysis revealed that the stress field was concentrated at the periphery of the pressurized region, where the pressure gradients were highest. The tangential stresses were compressive within the pressurized region and tensile at its periphery, where the pressure gradients are largest.