地面效应对汽车模型气动阻力的影响

黄志祥; 金华; 胡兴军; 王靖宇; 陈立

地面效应对汽车模型气动阻力的影响

1.
中国空气动力研究与发展中心空气动力学国家重点试验室, 四川绵阳 621000
2.
吉林大学汽车仿真与控制国家重点实验室, 吉林长春 130025

基金项目:

国家自然科学基金项目 11102070

空气动力学国家重点实验室项目 JBKY14010204

详细信息

作者简介:
黄志祥(1980-), 男, 湖北武汉人, 中国空气动力研究与发展中心助理研究员, 从事车辆空气动力学研究

中图分类号: U461.2
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出版历程
- 收稿日期: 2017-03-12
- 刊出日期: 2017-08-25

Influence of ground effect on air drag of car model

1.
State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang 621000, Sichuan, China
2.
State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130025, Jilin, China

More Information

Author Bio:
HUANG Zhi-xiang(1980-), male, assistant researcher, +86-816-2464704, xju331hzx@163.com

摘要

摘要: 为了获得地面效应对汽车模型气动阻力的影响, 在中国空气动力研究与发展中心Φ3.2m风洞对1∶3的MIRA汽车模型进行了风洞试验, 采用移动带作为统一的研究平台, 研究了地面静止与运动, 车轮静止与旋转, 以及车身不同离地间隙对气动阻力的影响; 模拟了横摆角为0°的无侧风工况, 固定试验风速为25m·s^-1, 变雷诺数试验风速为15~26 m·s^-1; 仅对汽车模型进行气动力测量, 主要关注气动阻力, 试验结果以量纲为1的气动阻力系数表示。分析结果表明: 当静止地面边界层厚度与车身底面离地间隙之比不大于0.32, 且车轮下表面与车身底面离地间隙之比(定义为量纲为1的离地间隙) 不大于0.37时, 静止地面比运动地面的气动阻力略小, 差异小于1.1%, 因此, 可以忽略地面状态对气动阻力的影响; 车轮静止比车轮旋转下的气动阻力略小, 差异小于2.1%, 因此, 在工程应用中, 当不能模拟车轮旋转时, 应考虑修正(增加) 气动阻力, 但修正量不宜大于2.1%;随着车轮下表面离地间隙的增加, 气动阻力总体呈现逐渐减小的趋势, 且在量纲为1的离地间隙为0.069~0.370时, 气动阻力差异小于2.0%, 因此, 在采用移动带开展汽车模型风洞试验时, 在确保车轮不与移动带带面接触的情况下, 车轮下表面到带面间隙应尽可能小。
- 汽车工程 /
- 地面效应 /
- 风洞试验 /
- 汽车模型 /
- 气动阻力 /
- 离地间隙
Abstract: In order to obtain the influence of ground effect on air drag of car model, for a 1∶3 scaled MIRA car model, a wind tunnel test was carried out inΦ3.2 m wind tunnel in China Aerodynamics Research and Development Center. A moving belt was taken as a unified research platform, and the influence of ground's fixed and moving states, wheels' motionless and rotating states, and different clearances of car body to ground plane on air drag was studied. The working condition of no cross wind that yaw angle is 0°was simulated, the fixed test wind velocity was 25 m·s^-1, and the changing Reynolds number's test wind velocity was 15-26 m·s^-1. The aerodynamic force of car model was only measured, air drag was mainly focused, and the test result was expressed by the dimensionless air drag coefficient. Analysis result shows that when the ratio of boundary layer thickness of fixed ground and the clearance of car bottom to ground is equal to or less than 0.32, the clearance ratio of wheel bottom and body bottom to ground is equalto or less than 0.37, the air drag for fixed ground is less than the value for moving ground, and the difference is less than 1.1%, so the impact of ground state on air drag can be ignored. The air drag for motionless wheel state is less than the value for rotation wheel, and the difference is less than 2.1%. So in the engineering application, when wheel rotation condition can't be simulated, correcting (increasing) air drag should be considered, but the allowance should be no more than 2.1%. With the increase of the clearance from wheel bottom to ground, air drag gradually decreases on the whole, and when the dimensionless clearance is 0.069-0.370, the difference of air drag is less than 2.0%. Thus in the wind tunnel test of car model using the moving belt, the clearance of wheel bottom to belt surface should be as small as possible under ensuring the contactless state of wheel bottom and moving belt surface.
- automotive engineering /
- ground effect /
- wind tunnel test /
- car model /
- air drag /
- ground clearance

HTML全文

图 1 风洞移动带系统

Figure 1. Moving belt system in wind tunnel

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图 2 汽车模型(单位: m)

Figure 2. Car model (unit: m)

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图 3 汽车模型安装

Figure 3. Installation of car model

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图 4 气动阻力系数

Figure 4. Air drag coefficients

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表 1 风洞参数

Table 1. Parameters of wind tunnel

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表 2 测力天平参数

Table 2. Parameters of force-measuring balance

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表 3 试验工况

Table 3. Test conditions

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表 4 地面状态对气动阻力系数的影响

Table 4. Influence of ground plane states on air drag coefficients

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表 5 车轮状态对气动阻力系数的影响

Table 5. Influence of wheel states on air drag coefficients

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表 6 离地间隙对气动阻力系数的影响

Table 6. Influence of clearances on air drag coefficients

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参考文献(25)

[1]	谢今明, 张扬军, 涂尚荣. 地面效应对汽车外部流动的影响[J]. 机械工程学报, 2003, 39 (3): 58-61. doi: 10.3321/j.issn:0577-6686.2003.03.013 XIE Jin-ming, ZHANG Yang-jun, TU Shang-rong. Numerical simulation study of ground effects on flow field around vehicle bodies[J]. Chinese Journal of Mechanical engineering, 2003, 39 (3): 58-61. (in Chinese). doi: 10.3321/j.issn:0577-6686.2003.03.013
[2]	庞加斌, 林志兴. TJ-2风洞汽车模型试验的修正方法[J]. 汽车工程, 2002, 24 (5): 371-375. doi: 10.3321/j.issn:1000-680X.2002.05.001 PANG Jia-bin, LIN Zhi-xing. Correction methods for automotive model tests in TJ-2wind tunnel[J]. Automotive Engineering, 2002, 24 (5): 371-375. (in Chinese). doi: 10.3321/j.issn:1000-680X.2002.05.001
[3]	王晓明, 赵又群. 车轮旋转对汽车流场影响的模拟研究[J]. 汽车科技, 2009 (4): 40-42, 39. doi: 10.3969/j.issn.1005-2550.2009.04.012 WANG Xiao-ming, ZHAO You-qun. Research on influence of rotating wheels on flow field around vehicle[J]. Automotive Technology, 2009 (4): 40-42, 39. (in Chinese). doi: 10.3969/j.issn.1005-2550.2009.04.012
[4]	谷正气, 林肖辉, 李伟平, 等. 车轮辐板形状对汽车气动阻力影响分析[J]. 科技导报, 2011, 29 (6): 57-61. https://www.cnki.com.cn/Article/CJFDTOTAL-KJDB201106025.htm GU Zheng-qi, LIN Xiao-hui, LI Wei-ping, et al. Effect of the shape of wheel spokes on vehicle aerodynamic performance[J]. Science and Technology Review, 2011, 29 (6): 57-61. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-KJDB201106025.htm
[5]	王夫亮, 尹章顺, 陈枫, 等. 车轮旋转条件下前轮导流板气动减阻机理研究[J]. 汽车工程, 2016, 38 (2): 157-162. https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC201602004.htm WANG Fu-liang, YIN Zhang-shun, CHEN Feng, et al. Aresearch on the aerodynamic drag reduction mechanism of front wheel deflectors in a condition of wheel rotation[J]. Automotive Engineering, 2016, 38 (2): 157-162. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC201602004.htm
[6]	COGOTTI A. Evolution of performance of an automotive wind tunnel[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2008, 96 (6/7): 667-700.
[7]	PAPENFUSS H D, KRONAST M. Moving-model technique used in automobile aerodynamics for measurement of ground effects[J]. Experiments in Fluids, 1991, 11 (2/3): 161-166.
[8]	BRUNGART T A, LAUCHLE G C, DEUTSCH S, et al. Effect of a moving wall on a fully developed, equilibrium turbulent boundary layer[J]. Experiments in Fluids, 2001, 30 (4): 418-425. doi: 10.1007/s003480000221
[9]	KWON H, PARK Y W, LEE D, et al. Wind tunnel experiments on Korean high-speed trains using various ground simulation techniques[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2001, 89 (13): 1179-1195. doi: 10.1016/S0167-6105(01)00107-6
[10]	YOSHIOKA S, KIKUCHI S, OHTA F, et al. Measurement of ground effect and boundary-layer transition by towing wind tunnel[J]. Fluid Dynamics Research, 2009, 41 (2): 1-12.
[11]	李征初, 杨炯, 梁鉴. Ф3.2m风洞活动地板系统研制[J]. 实验流体力学学报, 2011, 25 (4): 89-93. https://www.cnki.com.cn/Article/CJFDTOTAL-LTLC201104017.htm LI Zheng-chu, YANG Jiong, LIANG Jian. Development of moving belt floor in Ф3.2 m wind tunnel[J]. Journal of Experiments in Fluid Mechanics, 2011, 25 (4): 89-93. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-LTLC201104017.htm
[12]	TURNER T R. Wind tunnel investigation of a 3/8-scale automobile model over a moving-belt ground plane[R]. Washington DC: NASA, 1967.
[13]	BEARMAN P W, DE BEER D, HAMIDY E, et al. The effect of a moving floor on wind-tunnel simulation of road vehicles[C]∥SEA International. SAE International Congress and Exposition 1988. Warrendale: SAE International, 1988, DOI: 10.4271/880245.
[14]	庞加斌, 刘晓辉, 陈力, 等. 汽车风洞试验中的雷诺数、阻塞和边界层效应问题综述[J]. 汽车工程, 2009, 31 (7): 609-615. https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC200907008.htm PANG Jia-bin, LIU Xiao-hui, CHEN Li, et al. A review on Reynolds number, blockage and boundary layer effects in automotive wind tunnel tests[J]. Automotive Engineering, 2009, 31 (7): 609-615. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-QCGC200907008.htm
[15]	杨志刚, 丁宁, 李启良, 等. 移动带系统升力实验与数值研究[J]. 同济大学学报: 自然科学版, 2013, 41 (6): 900-903. https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201306018.htm YANG Zhi-gang, DING Ning, LI Qi-liang, et al. Experimental and numerical studies on moving-belt system lift force[J]. Journal of Tongji University: Natural Science, 2013, 41 (6): 900-903. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-TJDZ201306018.htm
[16]	BARBER T. Aerodynamic ground effect: a case study of the integration of CFD and experiments[J]. International Journal of Vehicle Design, 2006, 40 (4): 299-316.
[17]	BAYRAKTAR I, LANDMAN D, BAYRAKTAR T. Experimental measurements and computational solutions for aerodynamic forces on an Ahmed body at various ground clearances[C]∥ASME. ASME 2003International Mechanical Engineering Congress and Exposition. New York: ASME, 2003: 223-233.
[18]	JONES M A, SMITH F T. Fluid motion for car undertrays in ground effect[J]. Journal of Engineering Mathematics, 2003, 45 (3/4): 309-334. http://www.researchgate.net/profile/Frank_Smith13/publication/226167355_Fluid_motion_for_car_undertrays_in_ground_effect/links/0deec538630f4b01bf000000?ev=pub_ext_doc_dl_meta
[19]	杜子学, 陈振明. 移动地面条件下的微型车外流场数值模拟研究[J]. 华东交通大学学报, 2008, 25 (1): 16-19. https://www.cnki.com.cn/Article/CJFDTOTAL-HDJT200801008.htm DU Zi-xue, CHEN Zhen-ming. Numerical simulation study of the moving ground on external flow field around the mini-bus[J]. Journal of East China Jiaotong University, 2008, 25 (1): 16-19. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-HDJT200801008.htm
[20]	傅立敏, 扶原放. 轿车地面效应的数值模拟[J]. 吉林大学学报: 工学版, 2003, 33 (2): 11-14. https://www.cnki.com.cn/Article/CJFDTOTAL-JLGY200302003.htm FU Li-min, FU Yuan-fang. Numerical simulation on ground effect of simplified car model[J]. Journal of Jilin University: Engineering and Technology Edition, 2003, 33 (2): 11-14. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-JLGY200302003.htm
[21]	KRAJNOVI'CS, DAVIDSON L. Influence of floor motions in wind tunnels on the aerodynamics of road vehicles[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2005, 93 (9): 677-696.
[22]	COGOTTI A. A parametric study on the ground effect of a simplified car model[C]∥SEA International. SAE International Congress and Exposition 1998. Warrendale: SAE International, 1998, DOI: 10.4271/980031.
[23]	KATZ J. Calculation of the aerodynamic forces on automotive lifting surfaces[J]. Journal of Fluids Engineering, 1985, 107 (4): 438-443.
[24]	杨帆, 胡阳洋, 王建华. 重型卡车风阻优化[J]. 交通运输工程学报, 2013, 13 (6): 54-60. http://transport.chd.edu.cn/article/id/201306008 YANG Fan, HU Yang-yang, WANG Jian-hua. Optimization of wind resistance for heavy truck[J]. Journal of Traffic and Transportation Engineering, 2013, 13 (6): 54-60. (in Chinese). http://transport.chd.edu.cn/article/id/201306008
[25]	黄志祥, 陈立, 王桥. 尾部结构外形对轿车气动阻力影响的试验研究[J]. 汽车工程学报, 2015, 6 (5): 398-402. https://www.cnki.com.cn/Article/CJFDTOTAL-QCYK201506002.htm HUANG Zhi-xiang, CHEN Li, WANG Qiao. Wind tunnel test study on effects of tail structure and shape on vehicle aerodynamic drag[J]. Chinese Journal of Automotive Engineering, 2015, 6 (5): 398-402. (in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-QCYK201506002.htm