阶背车尾部结构对尾流场气动特性影响的仿真分析

doi:10.3969/j.issn.1674-8484.2021.03.005

摘要/Abstract

摘要：

为减少汽车气动阻力,改善阶背车尾部气动造型,探究了阶背车尾部结构对汽车气动特性的影响。采用Star-ccm+软件对阶背车MIRA模型的尾流场进行数值仿真,分析影响尾流场的关键车尾结构,确定了以车顶、后窗、侧窗、后备箱、底部上翘及尾部端面6个尾部结构为研究对象,探究了这些结构对气动特性的影响规律。从车尾整体角度设计车尾结构正交优化试验,进行各结构间相互影响下的车尾气动结构优化分析。结果表明:尾部上翘角、后窗倾角与车顶倾角是车尾气动结构设计与优化的关键;正交优化后的阶背车尾部结构,使气动阻尼系数减小14.4%。这说明,该结构设计改善了汽车尾流场。

关键词: 汽车结构, 汽车节能, 尾流场, 阶背车尾部结构, 数值仿真, 正交试验

Abstract:

The influence of notchback-car rear parts on aerodynamic characteristics was investigated to improve the aerodynamic shape and to reduce its aerodynamic resistance. The wake field of the MIRA model was simulated by using software Star-ccm+ to analyze the key rear structures affecting its flow field. The subjects were determined as six tail structures, including the roof angles, the rear window, the side window, the tail-up, the tail end face, and the trunk length, to investigate its influencing aerodynamic characteristics. An orthogonal optimization test of the rear structures was designed from the view of the whole rear structures. Optimized analysis of rear aerodynamic structures was developed with consideration of the interaction between each structure. The results show that the tail-up angle, the rear window angle, and the roof angle play key roles in designing the vehicle’s rear aerodynamic shape. The drag coefficient is reduced to 14.4% after the orthogonal optimization of the rear structures. Therefore, the optimal structure improves the vehicle rear flow.

Key words: vehicle structure, vehicle energy saving, wake field, notch back car tail structure, numerical simulation, orthogonal experiment

中图分类号:

TP391.9

屈贤, 余烽, 张金龙. 阶背车尾部结构对尾流场气动特性影响的仿真分析[J]. 汽车安全与节能学报, 2021, 12(3): 314-321.

QU Xian, YU Feng, ZHANG Jinlong. Simulation analysis for the effect of notchback-car rear structure on wake-field aerodynamic characteristics[J]. Journal of Automotive Safety and Energy, 2021, 12(3): 314-321.

图/表 13

参考文献 21

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计算域前部边界	速度入口 30 m/s
计算域后部边界	压力出口零梯度压力出口
计算域顶部及侧面边界	滑移壁面
计算域底部边界	非滑移壁面 30 m/s
半车身	非滑移壁面
半车身对称面计算域边界	对称面
速度松弛因子	0.7
压力松弛因子	0.1

计算域前部边界	速度入口 30 m/s
计算域后部边界	压力出口零梯度压力出口
计算域顶部及侧面边界	滑移壁面
计算域底部边界	非滑移壁面 30 m/s
半车身	非滑移壁面
半车身对称面计算域边界	对称面
速度松弛因子	0.7
压力松弛因子	0.1

结构编号	α / (°)	β / (°)	γ / (°)	δ / (°)	θ / (°)	l / mm
No.1	-20	0	60	-4	30	410
No.2	-10	5	65	-2	35	490
No.3	0	10	70	0	40	570
No.4	10	15	75	2	45	650
No.5	20	20	80	4	50	730

结构编号	α / (°)	β / (°)	γ / (°)	δ / (°)	θ / (°)	l / mm
No.1	-20	0	60	-4	30	410
No.2	-10	5	65	-2	35	490
No.3	0	10	70	0	40	570
No.4	10	15	75	2	45	650
No.5	20	20	80	4	50	730