Simulation analysis for the effect of notchback-car rear structure on wake-field aerodynamic characteristics

doi:10.3969/j.issn.1674-8484.2021.03.005

Abstract

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

CLC Number:

TP391.9

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.

Figures/Tables 13

References 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