Numerical Simulation Of Turbulent Flows And Spray Mixing Process In The Cylinders Of Internal Combustion Engines

In recent years, within a limited amount of time for computation and using computational fluid dynamics(CFD)methodologies for numerical calculations, the high-speed computers have the capabilities to simulate the overall behavior of the flow field in the engine. They can also predict the performance of an engine by adjusting the engine operational parameters.With the numerical simulation methods, this paper investigated Three-dimensional transient numerical simulation on an practical application in-line, 4-cylinder GDI(Gasoline Direct Injection)engine using professional CFD software--STAR-CD and ES-ICE module.Make the cylinder turbulent flow three-dimensional transient numerical simulation in the compression process(compression spray).The crank angle is between 180°CA~360°CA. Analysis the velocity vector field in the preliminary stage, earlier stage ,Middle period ,near TDC and TDC in the compression process. Compare the result with the experiment date that got from PIV in the same conditions. The simulation results match the experimental results very good.Make the cylinder turbulent flow three-dimensional transient numerical simulation in a large range with the crank angle between -170°CA~360°CA. Through the transient simulation results of the turbulent flow, analysis the process of the turbulent flow process. Change the turbulence model of the STAR-CD and turbulence parameter CMu, analysis the simulation results. The results showed that small changes will have significant impact on the flow field.Make the three-dimensional transient numerical simulation of the fuel injection and atomization process. Analysis the simulation results of the droplet distribution field, air-fuel ratio distribution field, velocity vector field, etc. The result shows that Good cylinder structural design is the necessary conditions for a lean burn. The shearing action of the jet flow come from the spray process is a major factor that impact the cylinder turbulent flow...