Analytical model of a tilting pad bearing including turbulence and fluid inertia effects

- An analytical model of a tilting pad bearing with effects of turbulence and fluid inertia is proposed.
- The inclusion of the fluid inertia effect has a small impact on calculation time.
- The proposed tilting pad bearing model can easily account changes in geometric parameters to test different setups.

This study presents the modeling of a tilting pad bearing using the short bearing approach. The model incorporates the effects of turbulence and fluid inertia, which influence the dynamic behavior of hydrodynamic bearings at high rotation speeds.The hydrodynamic forces of the bearing were calculated analytically, which is much faster than the one performed with the numerical integration. When comparing the runtime of the proposed model with the analytical model that has only the effect of turbulence, it is noticed that the time impact of including the fluid inertia effect is very small (approximately 2%).The influence of fluid inertia was verified by simulating a symmetrical rotor supported by a pair of tilting pad bearings. The results showed that the fluid inertia generates more hydrodynamic load, but does not significantly alter the bearing stiffness or damping. The proposed model was also compared with experimental tests and with a more complete numerical model. The results showed that the proposed analytical model approaches the results of the numerical model, although it does not consider important effects, such as the temperature variation of the lubricating film.After this analysis, we can conclude that the presented model can be used in the design optimization of tilting pad bearings. Although it is not a detailed model, its calculation speed is much superior to the other models.