Effects of Body Shape Parameters on Aerodynamic Drag Reduction for Pit Non-smooth Surface
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摘要: 采用数值模拟和风洞试验相结合的方法,研究车身造型参数对非光滑表面气动减阻的影响。将凹坑型非光滑结构布置在国际标准汽车简化模型——Ahmed模型的不同位置,通过分析不同位置非光滑的减阻效果,确定添加非光滑表面的位置。探讨改变Ahmed模型的后风窗角度、前端倒角和离地间隙情况下非光滑车身气动特性的变化规律,找出对于非光滑车身气动外形的最佳组合方案。结果显示,离地间隙的大小对非光滑减阻效果影响最大,改变离地间隙的模型比未改变离地间隙的非光滑表面Ahmed模型的气动阻力系数减小了4.3%。Abstract: The approach of combining the numerical simulation and wind tunnel experiment was employed to study the effects of the body shape parameters on the aerodynamic drag reduction for non-smooth surface. This paper applied pit non-smooth surface to different locations of the international standard car model-Ahmed, and by analyzing the non-smooth drag reduction effects in different locations to determine where to add non-smooth surface. The variations of aerodynamic characteristics of non-smooth body were investigated and the optimum combination scheme for non-smooth aerodynamic shape was determined in case of changing the angle of the Ahmed model's rear window, front chamfer and road clearance. The results show that the size of the road clearance is the most influential one for non-smooth drag reduction, and 4.3% drag reduction rate can be reached.
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[1] 谷正气.汽车空气动力学[M].北京:人民交通出版社,2005 Gu Z Q. Aerodynamics of road vehicles[M]. Beijing: People's Communications Press, 2005 (in Chinese) [2] Ren L Q, Han Z W, Tian L M, et al. Characteristics of the non-smooth surface morphology of living creatures and its application in agricultural engineering[J]. Design and Nature, 2004,6:275-284 [3] 陈魁.试验设计与分析[M].北京:清华大学出版社,2005 Chen K. Design and analysis of experiments[M]. Beijing:Tsinghua University Press, 2005 (in Chinese) [4] Ahmed S R, Ramm G, Faltin G. Some salient features of time averaged ground vehicle wake[R]. SAE Paper 840300, 1984 [5] Strachan R K, Knowles K, Lawson N J. A CFD and experimental study of an ahmed reference model[R]. SAE Paper, 2004-01-0442 [6] 王再宙,张春秀,郑淑芝,等.仿生非光滑凹坑表面模型建立及仿真研究[J].机床与液压,2011,39(1):92-94 Wang Z Z, Zhang C X, Zheng S Z, et al. Pits of bionic nonsmooth surface modeling and simulation research[J]. Machine Tool & Hydraulics, 2011,39(1):92-94 (in Chinese) [7] 张成春.旋成体仿生非光滑表面流场控制减阻研究[D].长春:吉林大学,2007 Zhang C C. Drag reduction of bodies of revolution by flow control using bionic non-smooth surface[D]. Changchun: Jinlin University, 2007 (in Chinese) [8] Lienhart H, Stoots C, Becker S. Flow and turbulence structures in the wake of a simplified car model (ahmed modell)[C]// New Results in Numerical and Experimental Fluid Mechanics Ⅲ, NNFM, 2002,77:323-330 [9] Hermann Lienhart and Stefan Becker. Flow and turbulence structure in the wake of a simplified car model[R]. SAE Paper, 2003-01-0656 [10] 黄向东.汽车空气动力学与车身造型[M].北京:人民交通出版社,2000:84-120 Huang X D. Automobile aerodynamics and body shape[M]. Beijing: People's Communications Press, 2000:84-120 (in Chinese) [11] Cogotti A. A parametric study on he ground effect of a simplified car model[R]. SAE, Paper, 980031 [12] 田丽梅.空气-旋成钝体界面非光滑减阻的仿生研究[D].长春:吉林大学,2005 Tian L M. Bionic study of drag reduction between air and non-smooth surface of blunt body of revolution model[D]. Changchun: Jinlin University,2005 (in Chinese)
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