Computational Fluid Dynamics (CFD) Analysis of Lubricant Oil Tank Sloshing of a High-Performance Car under Racetrack Maneuvers

The paper proposes a methodology to perform sloshing analyses through multidimensional Computational Fluid Dynamics (CFD), with particular focus on a lubricant tank of a high-performance sports car. Lubricant tanks are usually fed by a mixture of oil and air, which makes Volume of Fluid (VoF) models unsuitable for this kind of simulation. Hence, a different approach based on a Eulerian MultiPhase (EMP) model is investigated and adopted. In contrast to the VoF approach, which is the most consolidated technique to handle the numerical analysis of sloshing problems, the EMP accounts for interactions between liquid and gaseous phases, such as mixing and separation. It also reduces numerical constraints on time-step and mesh size. EMP is therefore applied to the analysis of a sports car lubricant tank where mist and foam formation and subsequent phase separation are of primary importance. Comparison between the EMP and VoF approach is performed on cases of increasing complexity. Firstly, a rectangular tank with internal baffles and under pitch oscillations, for which experimental measurements are available, is analyzed. The EMP approach shows improved responsiveness in representing both phase mixing and separation. Secondly, a current production lubricant oil tank, for which experimental test-rig measurements of foam percentage shortly upstream the feeding pump are available, confirms the ability of the EMP approach to quantitatively estimate foam formation. Thirdly, the analysis of a current production lubricant oil tank subject to typical racetrack maneuvers is performed. Such final step confirms the ability of the EMP approach to simulate complex interactions between the phases, which largely affect tank and lubricating circuit performance in high-performance sports car applications. Moreover, the EMP approach allows a massive reduction of computational time compared to VoF.