Research On The Non-smooth Aerodynamic Drag Reduction Characteristics For The Bus-like Body

With continuous constructio n of highways, fue l prices continue to rise, theaerodyna mic characteristics of passenger cars more and more get people’s attention.At present, the domestic and fore ign genera l by changing the bus fro nt endchamfering, after the wind window shape parameters and Angle and clearance fro mthe ground to reduce the aerodyna mic drag coeffic ient of passenger train, the researchof these methods, however, has been relative ly mature, reduce the body space of theair resistance is sma ll.Bio nics found that the anima ls whic h ha ve a smooth surface in the nature canmove quickly, such as sharks, dung beetles. Based on bionics, applying non-smoothsurface to the different locatio ns of the internationa l standard car model-Ahmed andus ing the method of CFD numerica l simulatio n to study the effect of non-smoothsurface of aerodynamic drag.This paper according to the selecting princ ip le of non-smooth surface, choosingpit type non-smooth surface as the research object, and applying p it non-smoothsurface to the different locations of the internatio na l standard car model-Ahmed,us ing the method of numerica l simulation research and analys is type pit non-smoothsurface effects on the aerodyna mic drag. Calculation results show that: the pit typenon-smooth surface arrange me nt in the tail has the best drag reduction affect, the dragreduction effect reached2.4%. Second ly, in this paper, the ca lculated results afterimporting the CFD software generated in the graphic processor, and the speed of theflow fie ld of Ahmed model vector diagra m, stress reprogram and flow chart wereanalyzed, and concluded that the drag reduction mecha nis m of non-smooth. Fina lly,this paper discusses the part shape parameters on the pit type, the influence ofnon-smooth unit cell model by changing the Ahmed the fro nt end of the chamfering,after the wind window at the bottom of the Angle, the clearance fro m the earth and thedistance between the wheel and the newborn parameter va lues for the analys is ofmodel parameters change on Ahmed model the influence of the aerodyna miccharacteristics of the flow fie ld, and to cha nge modeling parameters before and afterthe speed, pressure contours, and the flow chart, comparing the turbulent c loud imagein order to disc uss the mec hanis m of drag reduction. Calculation results s how that thechange o f the newborn of p its on the bottom of type has the greatest effect in the non-smooth surface drag reduction effect, when at the bottom of the newborn for50Ahmed minimum model of aerodynamic drag coeffic ient, the drag reduction ratereached9.6%.