Numerical simulation and extended validation of two-phase compressible flow in diesel injector nozzles

In this paper, the ability of a computational fluid dynamics code to reproduce cavitation phenomena accurately is checked by comparing data acquired by numerical simulations against those obtained from different experiments involving the mass flow, the momentum flux, and the effective injection velocity. Cavitation is modelled using a single-phase cavitation model based on a barotropic equation of state together with a homogeneous equilibrium assumption. In the research reported in this paper, the ability to use the code for actual diesel injector nozzle geometries and conditions has been checked and validated. The main contribution of the present investigation and what makes it different from previous work in the literature is the consideration of extended experimental data for validation purposes: the mass flow, the momentum flux at the nozzle exit, and the effective injection velocity. These are unique features in contrast with other publications, which normally take into account at the most, if at all, the cavitation morphology or the mass flow. The results obtained and their comparison with available experimental data show how the model is able to predict the behaviour of the fluid in such conditions with a high level of confidence.