Study on Interaction Influence of Tail Characteristic Parameters on Aerodynamic Drag and Global Optimization

Zhang Yong, Shi Jiaqi, Gu Zhengqi, Liu Shuichang, Mi Chengji

Abstract

In the aerodynamic drag reduction optimization of automobile tail structure,there is a phenomenon between geometrical characteristic parameters,which makes optimization become blind and complex. In order to ascertain the interaction law of the key geometrical parameters,this paper carried the CFD simulation research of the three main characteristic parameters on the back of the Ahmed model on the basis of the HD-2 wind tunnel experiment. In order to overcome the blindness of optimization,the integrated optimization platform was applied to optimize the tail characteristic parameters. The results show that the angle of the back inclination has the greatest contribution to drag reduction,the two sides rounded corners on the back has the smaller contribution,the contribution of the top corner of the back is the smallest. The influence of the change of three variables on the aerodynamic resistance is non-monotonic. When the values of the angle of the back inclination,the top corner of the back and the two sides rounded corners on the back are 13°,283 mm and 58 mm respectively,the drag reduction rate reaches 11.76%. This paper provides a reference for the study of the optimization of drag reduction in specific models.

 

 

 

Keywords: tail characteristic, interaction effect, Ahmed model,  drag reduction


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References


GU Z Q. Automobile aerodynamics [M]. Beijing:China Communications Press,2005:58—151 (In Chinese)

LIANG M,GU Z Q,ZHANG Y,et al. Study of automobile low resistance surface optimization based on hard points-skeleton constraint [J]. Journal of Wuhan University of Technology(Transportation Science and Engineering),2015,39(4):852—856.(In Chinese)

JOSEPH P,AMANDOL SE X,AIDER J L. Drag reduction on the 25 slant angle Ahmed reference body using pulsed jets [J]. Experiments in Fluids,2012,52(5):1169—1185.

WANG X W,ZHOU Y,PIN Y F,et al. Turbulent near wake of an Ahmed vehicle mode[l J]. Experiments in Fluids,2013,54(4):1— 19.

WANG H,ZHOU Y,ZOU C. Aerodynamic drag reduction of an Ahmed body based on deflectors[J]. Journal of Wind Engineering & Industrial Aerodynamics,2016,148:34—44.

ZHANG Y C,DU G M,ZHU H,et al. Strategy of active flow control to reduce aerodynamic drag with steady jet for 25° Ahmed mode[l J]. Journal of Tongji University (Nature Science Edition),2018,46(1):100—108. (In Chinese)

THACKER A,AUBRUN S,LEROY A,et al. Effects of suppressing the 3D separation on the rear slant on the flow structures around an Ahmed body[J]. Journal of Wind Engineering and Industrial Aero- dynamics,2012,107/108(6):237—243.

GRANDEMANGE M,CADOT O,COURBOIS A.A study of wake effects on the drag of Ahmed's squareback model at the industrial scale [J]. Journal of Wind Engineering and Industrial Aerodynamics,2015,145:282—291.

EVRARD A,CADOT O,HERBERT V,et al. Fluid force and symmetry breaking modes of a 3D bluff body with a base cavity[J]. Journal of Fluids and Structures,2016,61:99—114.

HE Y Z,L Y,LONG L H,et al. Investigation of flow characteris-tics and aerodynamic noise for an Ahmed body with different rear slant angles [J]. Journal of Tongji University (Nature Science Edition),2017,45(7):1022—1029. (In Chinese)

NI J,LIU Z Q,QIN H M,et al. Analysis and optimization on aerodynamic characteristics for a vehicle with biomimetic structure[J]. Machinery Design & Manufacture,2018,3(3):244—247. (In Chinese)

DUMAS L. CFD -based optimization for automotive aerodynamics[M]. Berlin:Springer,2008:4—7.

CHENG S Y. Aerodynamic stability of road vehicles in dynamic pitching motion[J]. Journal of Wind Engineering and Industrial Aero- dynamics,2013,122:146—156.

LAI Y Y. Parameter optimization theory and detailed examples[M]. Beijing:Beihang University Press,2012:96—149.(In Chinese)

PAN Z Y,GU Z Q,ZHANG Y,et al. Research on the simulation in-tegration and efficient optimizati -on of CFD flow field in automobiles[J]. Journal of Hunan University of Technology,2018,32(2): 31—37. ( In Chinese)


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