Assessment of Multi-Fluid, Eulerian Integral Thin Film and DPM Approaches for the Numerical Simulation of a Bearing Chamber

Abstract

In this work several computational approaches are tested for the two-phase simulation of the ELUBSYS bearing chamber in the high-speed regime - a 4-equation Eulerian multi-fluid model, a steady-state Eulerian Integral Thin Film (EITF) approach, a Discrete Parcel Method (DPM) approach and a simplified EITF-DPM coupled approach. While computationally expensive, the multi-fluid model captured the global liquid dynamics in the chamber and predicted that most of the oil is in the form of a thin film that flows on the stationary walls. The much more cost-efficient EITF approach achieved accurate results for the oil thickness distribution at the counter-current region but did not account for the large amounts of oil flowing out through the top vent. The DPM approach was used to assess the dispersed phase dynamics in both one-way and two-way coupling configurations, outlining a significant influence of the latter on the gas phase dynamics. Finally, the coupled EITF-DPM approach was able to overcome some of the limitations observed by its individual counterparts by predicting a continuous film throughout the chamber circumference and a higher vent outflow, while still retaining most of the expected film distribution characteristics in the bearing chamber.