Author(s)

MARCO NICOLA MASTRONE, FRANCO CONCLI

Abstract

Multiphase flows often involve additional complex physical phenomena to be considered, for example cavitation and aeration. These can arise in several applications as gear pumps, propellers, and gearboxes. In order to properly design such hydraulic systems, these aspects should be carefully considered in the design phase. In fact, these phenomena can lead to lower efficiency, excessive noise, and a rapid degradation of the mechanical system. While for cavitation analytical and numerical models are already available, aeration, which refers to the entrainment of air in another fluid in form of bubbles and/or foam, is more difficult to be quantified. Even experimentally niche equipment is required. However, thanks to recent developments in computer science, it is possible to approach these complex multiphase flows exploiting simulations’ tools. In this paper, a numerical approach based on Computational Fluid Dynamics (CFD) that includes the aeration phenomenon is presented. A new solver that accounts for the air entrapment in the fluid was implemented in the open source environment OpenFOAM®. The solver was applied on a test case to verify its behaviour and compared to a standard multiphase solver. The qualitative analysis suggests that the solver is capable of considering the amount of air entrapped in the fluid, thus opening a new way in the study of aeration.

Keywords

aeration, CFD, multiphase modelling, OpenFOAM