In the present study, a CFD model for cavitation simulation have been investigated and compared to experimental results in the case of 3-bladed industrial inducer. The model uses a multiphase approach, based on multiphase mixture assumption. A truncated form of Rayleigh-Plesset equation is used as a source term for the inter-phase mass transfer. The model allows a good prediction of the cavitation inception as well as the main cavity dimensions. The threshold corresponding to the head drop is also well predicted by the model. It was found that the cavitation induced head drop is mainly due to an increase of energy losses and a decrease of the supplied energy. The hydrodynamic mechanism of head drop is investigated through a global and local analysis of the flow field.