This paper presents results of the three-dimensional numerical modelling of the air/oil two-phase flow inside an aero engine bearing chamber. Simulations with different shaft speeds and chamber geometries were carried out and compared to experimental data in order to evaluate the potential and accuracy of the Volume-of-Fluid method for the modelling of complex multiphase flows.
For different bearing chamber scavenge offtake geometries and shaft speeds, the resulting scavenge characteristics, film thicknesses and flow pattern were analysed. Especially for the prediction of the scavenge characteristics, good agreement of numerical and experimental results was obtained. However, the accurate prediction of oil distribution and film thicknesses showed to be sensitive to the mesh resolution. Nevertheless, even with a coarse mesh, correct tendencies were observed.
With the application of a local Adaptive Mesh Refinement algorithm, the prediction of the oil film formation was improved. An additional influence of the surface-capturing scheme within the Volume-of-Fluid method on the solution accuracy has been identified.