EFFECT OF TURBULENCE DAMPING IN VOF SIMULATION OF AN AERO-ENGINE BEARING CHAMBER

In aero-engine bearing chambers, the modelling of shear driven oil films with the Volume of Fluid method poses significant challenges linked with the need to accurately capture the gas liquid interaction at the free surface. Typically, the modelling of the latter relies on a dedicated scalable source term, which is activated locally at the interface between the phases. Our latest published work focused on the application of a popular term of this kind known as turbulence damping, and raised some questions on the suitability of the choice of a high value for its scaling factor. In this paper, a lower turbulence damping factor value is proposed. The new results are evaluated against both the reference bearing chamber experimental data and the previously published numerical data. The results highlight that a transition from shear-driven to gravity-driven flow conditions takes place once the damping factor value is decreased. Considering the impact this may have on the accuracy of the numerical predictions, a strategy is proposed towards a better-informed choice of the turbulence damping factor, in particular when the expected flow conditions are unknown.