Modeling of Cavitation in Fuel Injectors with Single- and Two-Fluid Approaches

Abstract

In high-pressure fuel injection systems, cavitation is known to affect spray atomization processes. Modeling the cavitation phenomenon has become a necessity to ensure predictive quality and higher fidelity of the fuel spray simulations. Inside the fuel injectors, local pressures drop below the saturation pressure of fuels in regions of flow separations, such as inlet of holes and periphery of needles at low-lift conditions. Several cavitation models and multiphase modeling approaches have been employed in the literature to predict the extent of cavitation in the fuel injection systems. A review of these modeling approaches will be presented. Amongst the cavitation models, bubble-based and semi-empirical timescale-based ones are widely used. Mixture/single-fluid and Eulerian–Eulerian/two-fluid approaches have been adopted for fuel injection cavitation modeling. Two-fluid approach captures the interaction between the two phases, which is usually ignored in single-fluid approach. Comparative studies in the literature will be reviewed here to provide a comprehensive idea of the cavitation modeling approaches to the readers. The advantages and disadvantages of these models will be discussed in depth. Keeping in mind the conflicting requirements of accuracy and constraints of computational cost, recommendations will be provided for suitable cavitation modeling approaches.