Abstract
Aeration refers to the air entrapment in a second fluid. In mechanical transmissions (as gearboxes and turbines) it affects the reliability of the system by reducing its performance and leading to early failure of the components. Air bubbles decrease the effectiveness of the lubricant by directly impacting on its heat transfer capabilities. The analysis of aeration in gearboxes is traditionally based on experiments, which require niche equipment for its evaluation. The last decade has been characterized by huge improvements in the field of numerical calculus and computer technology. These led to the implementation of sophisticated virtual models capable of reproducing complex multiphase operating conditions. In the present work, Computational Fluid Dynamics (CFD) was exploited to study the effect of a new solver (implemented in the OpenFOAM® framework) that considers aeration. The solver was used for the simulation of a real gearbox in which aeration was observed. The results were analysed qualitatively in terms of amount of increase of the lubricant mixture volume, and quantitatively in terms of power dissipation estimation. The promising outcomes of this analysis suggests that this tool can be possibly exploited to have a deeper insight in the aeration phenomenon.