Possibilities and limits of modeling cavitation in high-pressure homogenizers – a validation study

Abstract

High-pressure homogenizers are widely used in industrial processes to produce emulsions with small droplet sizes. During the process, cavitation occurs under industrial process conditions. In order to investigate the flow conditions inside a homogenizer geometry, CFD simulations are commonly used, since it is not possible to evaluate local flow conditions experimentally. However, these studies have, so far, investigated flow under non-cavitating conditions, which do not adequately reflect industrial process conditions. This study investigates the extent to which the two cavitation models, the Schnerr-Sauer model and the Zwart-Gerber-Belamri model, can represent cavitation in the gap of the homogenizing geometry using RANS simulation. Simulations are validated with experimental cavitation visualization data. Results show that the Schnerr-Sauer model (with appropriately set modeling constants) is able to accurately predict the operating conditions responsible for cavitation inception in the valve, as well as the length and width of the cavitation zone.