Computational Fluid Dynamics Modeling of Gaseous Cavitation in Lubricating Vane Pumps: An Approach Based on Dimensional Analysis

This paper addresses the problem of computational-fluid-dynamics (CFD) modeling of gaseous cavitation (GC) in lubricating positive-displacement pumps (PDPs). It is important for designers and analysts to predict the dynamic features of air release/dissolution processes which characterize this phenomenon along with its effect on filling capability and noise-vibration-harshness (NVH) behaviour of the machine. The focus is on the empirical tuning of the commercial homogeneous-flow cavitation model known as Dissolved Gas Model (DGM). Considering an automotive case study of a balanced vane pump (BVP), the effects of air modeling on numerical predictions of discharge flow/pressure ripple and volumetric efficiency have been studied. The tuning time parameters of the model have been correlated to the machine Reynolds number as part of a simplified theoretical background based on dimensional analysis. Considering experimental data at different operating conditions, the tuned model has shown a good capacity in predicting the pressure ripple and the flow rate at the discharge of the pump.