This paper aims to clarify the growth of bubble nuclei in water flowing through the two-dimensional nozzle which is a model of diesel fuel injector nozzle. The nuclei growth is initiated due to tension induced by the sudden pressure drop at the sharp corner of the nozzle edge and it is investigated by means of experiment, CFD flow simulation and bubble dynamics. In the experiment, the observation section of the nozzle is around sharp corner to generate bubbles, and once cavitated, the water cannot return to the observation section. A single-phase water flow is simulated using LES-based CFD to obtain the velocity distribution at the sharp corner in the nozzle edge, flow separation, and vortex formation downstream of the separation point, pressure distribution before and after the sharp corner in the nozzle edge. The growth mechanism of bubble nuclei is clarified with Blake’s cavitation threshold theory and Rayleigh-Plesset equation in the CFD-flow field under experimental conditions. Finally, the bubble nuclei attain the critical radii a little downstream of the sharp corner in the nozzle and then explosively start growing in cases where Blake’s threshold is fulfilled.
