Numerical investigation of transient hole-to-hole variation in cavitation regimes inside a multi-hole diesel nozzle

Dynamics of in-nozzle flow are known to have crucial impacts on the spray structure, and thus hole-to-hole variation in transient cavitating is strongly suspected being a source undesirable asymmetries. This study focuses effects needle motion evolution cavitation regimes. For verifying numerical models, simulation results obtained using Winklhofer throttle “U” real-size two-hole optical nozzle were validated against available experimental data mass rate at exit geometrical/string regions. Two different patterns string defined as “needle” “hole connecting” experiments. Then characteristics inside five-hole injector studied under lift off-axis models. Results show that originated from tip and/or hole then developed into orifice lower lifts, ones connecting orifices through sac tended form higher lifts with weaker intensity shorter duration. Meanwhile, both depended structure vortex flow. Furthermore, geometrical occur within simulated injector, all single-phase flow, regimes can simultaneously 1, 2 3 respectively due radial displacement.