The Research On Sensitivity About Aerodynamic Characteristics Of Micro-bus Based On Morph And DOE

Aerodynamic performance of the vehicle has a critical influence on the car’spower, operational stability, comfort and fuel economy performance. Especially sincethe beginning of the21st century, with the energy crisis further exacerbated, energyprices continue to rise, all the cars are faced with the requirement to reduceresistance. At present, the research about drag reduction and energy-saving are focuson the car, but not micro-buses, which are with larger drag coefficient. With thefurther expansion of the micro-buses market, the vast majority of car manufacturers inChina have large quantities of micro-buses. However, due to the special structuralcharacteristics of the micro-buses: without a general car fairing body, nor a largerfrontal area, resulting in poor aerodynamic performance of the vehicle and largeaerodynamic drag. At high speeds, aerodynamic drag increases rapidly, leading tosharp increase in fuel consumption. Therefore, carrying out a study about therelationship between the aerodynamic drag coefficient of micro-buses and the bodyshape does have a major engineering significance.For domestic research on flow field around automobile in vehicle factory: Ittakes o long time from the CAD geometry cleanup to the results of the analysis.Especially, grid re-divided is required for every shape change, the overall efficiency isnot high. In this paper, an interface is structured between Sculptor, which is a existinggrid deformation tool and CFD, then an effective process is established. Also shapestructure parameters and automatic mesh morphing technology are both takenconsidered in automotive design thus shortening the pre-processing part of the time.Compared to previous studies, computational model used in this paper comesfrom the project, the calculation method used has passed the test of the standard, theresults are more reliable, the main innovations are：(1) In the process using the Sculptor Morphing technology to the analysis of theoutflow automotive field,time used to redraw the mesh by human has beenomitted,and the quality of the mesh is guaranteed. Thereby the process can increasethe efficiency of the vehicle development process and shorten the development cycle.(2) Shape structural change, grid resetting, CFD analysis are connected forclosed-loop by Isight platform,then a automated workflow is realized in this paper. Inaerodynamics assessment of vehicle development,it can obtain the degree of influence that different shapes for the drag coefficient,which has a very significant engineeringsignificance.