Simulation Analysis on Cavitation Flow in a Diesel Engine Nozzle

The cavitation flow in a nozzle at steady spray of a diesel engine was simulated,and the formation mechanism and distribution of cavitation inside the nozzle were analyzed using mixed multiphase flow model coupled with cavitation model.Based on this model,the effects of geometric and structural parameters,such as injection pressure,rear pressure,length-diameter ratio,inlet round angle-radius ratio and non-axis symmetry of nozzle,on the distribution of the cavitation inside the nozzle are analyzed.Simulation results show that better atomization can be realized by enhancing the cavitation intensity via increasing the injection pressure difference or decreasing the nozzle inlet round angle-radius ratio.Uniform distribution of cavitation at the nozzle exit section is obtained by increasing length-diameter ratio and leads to the improvement of atomization.