Numerical Simulation Of Van External Flow Field

The van are playing a more and more important role in the transportation industry,with the construction of the highway and the increase number of van. Lots of attentions have been paid on dynamic characteristics,fuel economy and Steering stability of van. Subsequently, the requirement of the aerodynamic of the van become higher. By using the soft of computational fluid dynamics, the external flow field characteristics of a van has been conducted, and meanwhile the source of resistance of the van are analyzed. At last, by optimizing structure parameters,the aerodynamic drag can be reduced.A detailed study of the aerodynamic characteristics of the van and outflow field characteristics has been conducted. First, The numerical simulation on the external flow field of Ahmed body are conducted,with the κ-ε model, and the pressure distribution, and the tail of the flow field of the Ahmed body are discussed. Through the comparision of the results of simulation and the experiment, The relative error less than5%and the simulation accuracy is meet requirement.Second, The numerical simulation on the external flow field of the van are conducted,with the κ-ε model, and the external flow field of trucks are analyzed in detail,including the pressure distribution, streamline, tail vortex structure, friction factor and turbulent kinetic energy, etc. And the main influence factors of the aerodynamic drag of the van are also analysed. Finally, the structure parameters of the van are researched. Based on the influence of the height of dome and the distance between dome and the front of van on the aerodynamic van and the dip Angle of car tail, the structure are optimized.By analysed the outflow field of the improved van,the conclusion can be drawed that the Aerodynamic drag decrease15.16%between the improved van and the original.Through the simulation calculation,the outflow field of the van are analysed. And the reasonable height of dome and distance between dome and the front of the van and the dip Angle of car tail are also put forward.and all this work can has some reference on reduce the resistance of the van.