The paper presents the ongoing research on cavitation modelling so far which includes validation studies of the gas content effect on the cavitation characteristics of the pump. Cavitation flow characteristics are modeled by performing Computational Fluid Dynamics (CFD) simulations using Schnerr-Sauer cavitation model implementing empirical coefficients. As a result, it was found that the inclusion of the third phase into the cavitation model significantly affects the cavitation characteristics of the pump and the NPSH.