The Research Of Van Drag Reduction

With China’s rapid economic development，more and more highway is beingconstructed.By the end of2010,The mileage of China’s highway has reached to71000kilometers rfom41000kilometers at the end of the Fifth Plan.Due to theincreasement of highway and the development of automobile technology,the speed ofautomobile is becoming faster and faster.As the speed increases,the aerodynamicdrag of the vehicle suffered also increases.Studies show that:when the vehicle speedexceeds70km/h,the aerodynamic drag is one of the main factors affecting theperformance of the car. Compared to the car,the truck has larger aerodynamicdrag.As the main component of the trucks,the van will suffer even greater airresistance due to its larger frontal area at high speed.Reducing the van’s airresistance coefficient has a very realistic and important significance.The paper aims to study which type of grid and turbulence model are proper toestablish the van external lfow ifled simulation and design correspondingaerodynamic additional device to optimize truck air drag coeiffcient,In order toachieve maximum drag reduction effect,The optimization method is also used tooptimize the attachment of the truck.The main contents of the paper are as follows:l，The GTS standard model is established,Through the comparison of wind tunnelexperimental data and simulation results,it is obtained that van external lfow ifeldsimulation is more accurate with tetrahedral mesh and SST k-co turbulence model.2，An van solid model is established.The reasons for greater air resistance oftruck are studied,and some suggestions to reducing truck air resistance are alsooffered.3,Drag reduction effect of the ladder trailing vortex generator is studied.the sizeof the trailing vortex generator is optimized by the modern design methods.Firstlythe sample points are selected through the Latin square method，based on the samplepoints the Kriging approximate equation is established，and then the multi-islandgenetic algorithm is used to optimize the approximation mo d e1. F in a lly, the size of thethe trailing vortex generator reached the maximum drag reduction effect.