摘要
为探索车身非光滑表面特征参数的优化设计方法,在MIRA阶梯背模型尾部分别布置凹坑型、凸包型和沟槽型非光滑表面,进行计算仿真和风洞模型试验对比分析不同非光滑单元的减阻效果。以非光滑单元体间距与高度为设计变量,以模型气动阻力系数为优化目标,采用拉丁超抽样方法进行样本设计,建立Kringing近似模型并检验拟合精度,运用NSGA-II遗传优化算法分别对凹坑型、凸包型和沟槽型非光滑表面特征参数进行优化。对比优化前后流场参数,分析车身非光滑表面减阻的机理。仿真结果和风洞试验数据表明优化后的凹坑、凸包及沟槽型非光滑表面模型的气动阻力均进一步减小,减阻率分别达到6.92%、4.03%、4.24%,减阻效果明显。
To explore the optimization and design method of non-smooth surface on vehicle body,dimple,convex and groove non-smooth surfaces are respectively arranged at the rear of the MIRA model.CFD and wind tunnel test are adopted to analysis the reduction effects and the drag reduction effects are compared with the original smooth model.The results show that the aerodynamic drag decreases with the decoration of non-smooth surface.In the article,the distance and the height of non-smooth surface are considered as the design variables.Aerodynamic drag is the objective evaluation functions.Sample points are obtained by Latin hypercube sampling method and Kriging approximate model is set up according to sample points and response values.The fitting precision of approximate model is tested.NSGA-II is used in genetic algorithms.Drag reduction effects and mechanism before and after optimization of non-smooth surface model are compared and analyzed.The simulation and test results both show that the aerodynamic drag coefficient are further decreased and the aerodynamic drag reduction rate of dimple,convex and groove nonsmooth surface are 6.92%,4.03%,4.24%.
出处
《重庆大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2015年第4期10-17,共8页
Journal of Chongqing University
基金
国家自然科学基金资助项目(51375155)
湖南省自然科学基金资助项目(12JJ3041)~~
关键词
车身
气动减阻
非光滑表面
参数优化
近似模型
automobile body
aerodynamic drag reduction
non-smooth surface
parameter optimization
approximate model
