Cavitation has a potential effect on the performance of full circle journal bearings. This paper studied the effects of cavitation on steadily loaded journal bearings, with the purpose of analyzing the necessity of adopting a mass-conserving model for ordinary journal bearings. The Christopherson’s method and Elrod cavitation algorithm were implemented to represent the non-mass-conserving Reynolds model and the mass-conserving Jakobsson-Floberg-Olsson (JFO) theory, respectively. The difference in the oil film reformation boundaries predicted by the two methods was focused on. The typical performance parameters including oil film pressure, load-carrying capacity, attitude angle, friction force, and leakage were comprehensively compared. The results show that the load-carrying capacity is improved by the decrease in cavitation pressure, and the effect is significant in lightly loaded cavitated bearings. In non-cavitated cases and the cavitated cases with intermediate and heavy loads, the difference between the Reynolds model and the JFO theory can be effectively ignored, but the accuracy of the leakage predicted using the Reynolds model should be carefully evaluated.

Nonuniform mesh is beneficial to reduce computational cost and improve the resolution of the interest area. In the paper, a cell-based adaptive mesh refinement (AMR) method was developed for bearing cavitation simulation. The bearing mesh can be optimized by local refinement and coarsening, allowing for a reasonable solution with special purpose. The AMR algorithm was constructed based on a quadtree data structure with a Z-order filling curve managing cells. The hybrids of interpolation schemes on hanging nodes were applied. A cell matching method was used to handle periodic boundary conditions. The difference schemes at the nonuniform mesh for the universal Reynolds equation were derived. Ausas’ cavitation algorithm was integrated into the AMR algorithm. The Richardson extrapolation method was employed as an a posteriori error estimation to guide the areas where they need to be refined. The cases of a journal bearing and a thrust bearing were studied. The results showed that the AMR method provided nearly the same accuracy results compared with the uniform mesh, while the number of mesh was reduced to 50–60% of the number of the uniform mesh. The computational efficiency was effectively improved. The AMR method is suggested to be a potential tool for bearing cavitation simulation.

This paper proposed a new approach to Reynolds boundary condition approximation in journal bearing CFD analysis. Dynamic mesh method was applied to approach the location where the rupture of oil film or cavitation started. A numerical model of half bearing geometry was constructed to obtain the Half-Sommerfeld solution. Using the solution, a pseudo-transient analysis was subsequently conducted. The boundary at the minimum film thickness was treated as the moving boundary. The Reynolds boundary condition was satisfied at a certain point when the pressure derivative of boundary nodes approached zero over the course of mesh growth. The analytical results were compared against the results of published works. It was discovered that the resulting cavitation angle and oil film pressure were consistent with those obtained by taking the Reynolds equation approach, with only slight differences observed from those obtained via the cavitation experiments and models. The proposed method is an extension of Reynolds boundary condition according to the CFD approach. It is considered an alternative to other cavitation models intended for journal bearings.

The cavitation has a potential effect on the performance of surface-textured bearings. The traditional mass-conserving cavitation algorithms based on the Gauss-Seidel iteration method become slow as the grid increases. The computation time is unacceptable once the grid consists of a large array of textures. This study developed an explicit cavitation multigrid algorithm to accelerate the simulation of surface-textured bearings. The algorithm was based on the Ausas cavitation algorithm with the advantage of a matrix-free implementation. Novel numerical technologies were developed to overcome the difficulty of the floating free boundaries caused by the cavitation characteristics. An example of surface-dimpled thrust bearings was studied to analyze the algorithm efficiency. The algorithm is shown to be approximate optimal under reasonable solution parameters. It is an alternative to other cavitation algorithms.