Three-dimensional Numerical Simulation Of Diesel Engine Injection Nozzle Cavitation Flow Based On CFD

Combustion process in diesel engine is mainly diffusion combustion, the speed ofcombustible mixture formation, which depends on the quality of fuel atomization, controlsthe burning rate. In other words, atomization characteristics of the spray play a key role indiesel engine combustion and emissions. It is necessary to study the phenomenon of thecavitation in injector nozzle.In this paper, a typical direct injection diesel engine nozzle is studied. Using theAVL-FIRE software, different flow parameters and geometry for the nozzle how to effectsinternal flow state of the nozzle is figure out1Compared the simulation results with the engine bench test data to verify theaccuracy of three-dimensional simulation model. Internal flow of the model is analyzed;2Different flow parameters and geometry for the nozzle how to effects the fuelnozzle internal flow state is analyzed. By changing the inlet pressure, nozzle diameter,nozzle diameter ratio (L/D) and the nozzle angle, different boundary conditions how toeffects fuel injection nozzle internal pressure, speed and turbulent kinetic energydistribution is figure out;3Based on the internal flow state of the nozzle, the formation and distribution ofthe cavitation in injector nozzle, distribution of velocity and Gas volume fraction at theexit of the nozzle are analyzed;The results show that the size and structure of the nozzle and the injection conditionshave a significant impact on internal nozzle transient flow characteristics, spraycharacteristics can be improved by optimizing the injection conditions and spray nozzlesize and structure.