Modelling the multiphase flow in hydrocyclones JILI 2017 The thesis assesses the applicability of numerical approaches in modelling the multiphase flow in hydrocyclones at a wide range of feed solid concentrations. Based on the selected numerical approach, the effects of material density and its interactions with the cyclone body size and inlet feed type are investigated. Further, the effect of feed size distribution on the multiphase flow and performance of hydrocyclones is studied. Finally, the numerical results, including those generated in this PhD projects and other PhD projects, are then included in the numerical database based on which a PC-based predictive model is developed.