吉林大学学报(工学版) ›› 2020, Vol. 50 ›› Issue (5): 1635-1644.doi: 10.13229/j.cnki.jdxbgxb20190401

• 车辆工程·机械工程 • 上一篇    

基于双稳态尾迹的方背Ahmed模型减阻

杨志刚1,2,3(),范亚军1,2,夏超1,2(),储世俊1,2,单希壮1,2   

  1. 1.同济大学 汽车学院，上海 201804
    2.同济大学 上海地面交通工具风洞中心，上海 201804
    3.北京民用飞机技术研究中心，北京 102211
  • 收稿日期:2019-04-26 出版日期:2020-09-01 发布日期:2020-09-16
  • 通讯作者: 夏超 E-mail:zhigangyang@tongji.edu.cn;chao.xia@tongji.edu.cn
  • 作者简介:杨志刚(1961-)，男，教授，博士生导师.研究方向：车辆空气动力学.Email:zhigangyang@tongji.edu.cn
  • 基金资助:
    上海市重点实验室项目(18DZ2273300);上海市专业技术服务平台项目(19DZ2290400);国家自然科学基金项目(51905381)

Drag reduction of a square⁃back Ahmed model based on bi⁃stable wake

Zhi-gang YANG1,2,3(),Ya-jun FAN1,2,Chao XIA1,2(),Shi-jun CHU1,2,Xi-zhuang SHAN1,2   

  1. 1.School of Automotive Studies, Tongji University, Shanghai 201804, China
    2.Shanghai Automotive Wind Tunnel Center, Tongji University, Shanghai 201804, China
    3.Beijing Aeronautical Science & Technology Research Institute, Beijing 102211, China
  • Received:2019-04-26 Online:2020-09-01 Published:2020-09-16
  • Contact: Chao XIA E-mail:zhigangyang@tongji.edu.cn;chao.xia@tongji.edu.cn

RICH HTML

 7   

PDF (PC)

15839

摘要：

利用压力传感器和粒子图像测速技术(PIV)对1/4缩比的方背Ahmed模型以及加装船尾结构的模型尾迹进行了精细测量和统计分析，实验雷诺数为9.6×104。背部瞬时压力的统计分析表明：方背Ahmed模型的尾迹在水平方向上呈现出双稳态的特征，即两种打破对称的稳定状态交替出现，每种稳定状态可维持较长的时间尺度。处于两种稳定状态时，背部大概率地呈现出较低的压力，而处于过渡态时相反。通过PIV在水平面的测量，瞬时流场和条件平均的结果均捕捉到了双稳态的流场特征。在模型尾部增加船尾结构后，尾迹的双稳态现象随着船尾长度的增加逐渐被抑制，尾迹涡结构趋于对称，同时尾迹宽度变窄，涡脱落强度减弱，继而造成背压提升，阻力减小。

关键词: 车辆工程, 方背Ahmed模型, 双稳态尾迹, 船尾结构, 粒子图像测速技术

Abstract:

The wake of 1/4 scale square back Ahmed body with or without boat-tail structure was investigated at ReH=9.6×104 by pressure sensor and particle image velocimetry(PIV). The statistical analysis of the instantaneous pressure on the back shows that the wake presents a bi-stable behavior in the horizontal direction, characterized by alternating occurrence of two symmetry-breaking stable states, each can maintain a relatively long-time duration. During the two stable states, a lower pressure on the back presents a high probability, while in the switch state the pressure on the back is higher. The bi-stable behavior was also observed by instantaneous and conditional average PIV results of flow field in the horizontal plane. With boat-tail structure added at the model base, the bi-stable behavior of the wake is gradually suppressed with the increase in the boat-tail length, and the wake vortex structure tends to be symmetrical, the wake width becomes narrow, the vortex shedding strength weakens, leading to higher back pressure and lower drag coefficient.

Key words: vehicle engineering, square-back Ahmed model, bi-stable wake, boat-tail structure, particle image velocimetry(PIV)

中图分类号: 

  • U461.1

图1

试验装置设置及坐标系"

图2

船尾结构"

图3

阻力系数随船尾结构长度的变化"

图4

模型背部平均压力系数Cp"

图5

背部对称点的瞬时压力系数"

图6

背部测压点"

图7

压力梯度的轨迹相图"

图8

不同长度船尾结构的水平方向背压分布时空图"

图9

尾迹区横截面z/H=0.67处的瞬时涡量场及流线"

图10

尾迹区横截面z/H=0.67处的条件平均速度场"

图11

尾迹区横截面z/H=0.67处的速度场"

图12

尾迹区纵截面y/H=0处的瞬时涡量场及流线"

图13

尾迹区纵截面y/H=0处的平均速度场"

1 Ahmed S R, Ramm G, Faltin G. Some salient features of the time-averaged ground vehicle wake[C]∥ SAE Technical Paper, 840300, 1984.
2 Choi H, Lee J, Park H. Aerodynamics of heavy vehicles[J]. Annual Review of Fluid Mechanics, 2014, 46(1): 441-468.
3 Khalighi B, Zhang S, Koromilas C, et al. Experimental and computational study of unsteady wake flow behind a bluff body with a drag reduction device[J]. SAE Technical Paper, 2001-01-1042.
4 Mcarthur D, Burton D, Thompson M, et al. On the near wake of a simplified heavy vehicle[J]. Journal of Fluids and Structures, 2016, 66: 293-314.
5 崔文诗, 杨志刚, 王国俊, 等. 不同后倾角三维车辆的尾迹非定常流动分析[J]. 吉林大学学报: 工学版, 2017, 47(3): 717-724.
Cui Wen-shi, Yang Zhi-gang, Wang Guo-jun, et al. Unsteady flow analysis for wakes of three-dimensional vehicles with different rear slant angles[J]. Journal of Jilin University(Engineering and Technology Edition), 2017, 47(3): 717-724.
6 Grandemange M, Gohlke M, Cadot O. Turbulent wake past a three-dimensional blunt body. Part 1: global modes and bi-stability[J]. Journal of Fluid Mechanics, 2013, 722: 51-84.
7 Grandemange M, Cadot O, Gohlke M. Reflectional symmetry breaking of the separated flow over three-dimensional bluff bodies[J]. Physical Review E, 2012, 86(3): 035302.
8 Grandemange M, Gohlke M, Cadot O. Bi-stability in the turbulent wake past parallelepiped bodies with various aspect ratios and wall effects[J]. Physics of Fluids, 2013, 25(9): 095103.
9 Wang H F, Zhou Y. The finite-length square cylinder near wake[J]. Journal of Fluid Mechanics, 2009, 638: 453-490.
10 王汉封, 徐胜金. 用POD方法研究有限长正方形棱柱尾流的双稳态现象[J]. 空气动力学学报, 2014, 32(6): 827-833.
Wang Han-feng, Xu Sheng-jin. On the bistable phenomenon of a finite length square cylinder wake with POD method[J]. ACTA Aerodynamica Sinica, 2014, 32(6): 827-833.
11 王汉封, 徐萌霞. 有限长正方形棱柱绕流的双稳态现象[J]. 力学与实践, 2013, 35(3): 46-50.
Wang Han-feng, Xu Meng-xia. Bistable phenomenon of the flow around a finite-length square prism[J]. Mechanics in Engineering, 2013, 35(3): 46-50.
12 Gilliéron P, Kourta A. Aerodynamic drag reduction by vertical splitter plates[J]. Experiments in Fluids, 2010, 48(1): 1-16.
13 王勋年, 李士伟, 陈立. 采用尾部隔板降低类客车体阻力的研究[J]. 实验流体力学, 2011, 25(2): 58-62.
Wang Xun-nian, Li Shi-wei, Chen Li. Investigation on reducing drag of the bus-like body using tail clapboards[J]. Journal of Experiments in Fluid Mechanics, 2011, 25(2): 58-62.
14 李士伟. 类客车体气动特性及减阻措施的试验研究和数值模拟[D]. 绵阳: 中国空气动力研究与发展中心, 2010.
Li Shi-wei. Experimental study and numericial simulation of the aerodynamics performance and drag reduction measurement for the bus-like body[D]. Mianyang: China Aerodynamics Research and Development Center, 2010.
15 Evrard A, Cadot O, Herbert V, et al. Fluid force and symmetry breaking modes of a 3D bluff body with a base cavity[J]. Journal of Fluids and Structures, 2016, 61: 99-114.
16 Verzicco R, Fatica M, Iaccarino G, et al. Large eddy simulation of a road vehicle with drag-reduction devices[J]. AIAA Journal, 2002, 40(12): 2447-2455.
17 Khalighi B, Chen K H, Iaccarino G. Unsteady aerodynamic flow investigation around a simplified square-back road vehicle with drag reduction devices[J]. Journal of Fluids Engineering, 2012, 134(6): 061101.
18 Khalighi B, Balkanyi S R, Bernal L P. Experimental investigation of aerodynamic flow over a bluff body in ground proximity with drag reduction devices[J]. International Journal of Aerodynamics, 2013, 3(4): 217-233.
19 张英朝, 杜冠茂, 田思, 等. 35°Ahmed模型气动射流减阻主动控制[J]. 吉林大学学报: 工学版, 2019, 49(2): 351-358.
Zhang Ying-chao, Du Guan-mao, Tian Si, et al. Active flow control of 35° Ahmed model to reduce aerodynamic drag with steady jet[J]. Journal of Jilin University(Engineering and Technology Edition), 2019, 49(2): 351-358.
20 Roumeas M, Gilliéron P, Kourta A. Analysis and control of the near-wake flow over a square-back geometry[J]. Computers & Fluids, 2009, 38(1): 60-70.
21 Wassen E, Eichinger S, Thiele F. Simulation of active drag reduction for a square-back vehicle[J]. Notes on Numerical Fluid Mechanics & Multidisciplinary Design, 2010(108): 241-255.
22 Littlewood R P, Passmore M A. Aerodynamic drag reduction of a simplified squareback vehicle using steady blowing[J]. Experiments in Fluids, 2012, 53(2): 519-529.
23 Grandemange M, Gohlke M, Cadot O. Turbulent wake past a three-dimensional blunt body. Part 2: experimental sensitivity analysis[J]. Journal of Fluid Mechanics, 2014, 752: 439-461.
24 Evstafyeva O, Morgans A S, Dalla L L. Simulation and feedback control of the Ahmed body flow exhibiting symmetry breaking behaviour[J]. Journal of Fluid Mechanics, 2017, 817: 2-12.
25 Brackston R D, García de la Cruz J M, Wynn A, et al. Stochastic modelling and feedback control of bistability in a turbulent bluff body wake[J]. Journal of Fluid Mechanics, 2016, 802: 726-749.
26 Volpe R, Devinant P, Kourta A. Experimental characterization of the unsteady natural wake of the fullscale square back Ahmed body: flow bistability and spectral analysis[J]. Experiments in Fluids, 2015, 56(5): 1-22.
27 Khalighi B, Chen K, Iaccarino G. Unsteady aerodynamic flow investigation around a simplified square-back road vehicle with drag reduction devices[J]. Journal of Fluids Engineering, 2012, 134(6): 061101.
[1] 杜常清,曹锡良,何彪,任卫群. 基于混合粒子群算法的双离合变速器参数优化设计[J]. 吉林大学学报(工学版), 2020, 50(5): 1556-1564.
[2] 李静,石求军,洪良,刘鹏. 基于车辆状态估计的商用车ESC神经网络滑模控制[J]. 吉林大学学报(工学版), 2020, 50(5): 1545-1555.
[3] 高菲,肖阳,张文华,祁锦轩,李子樵,马骁远. 高温和荷电状态对锂离子电池单体力学响应的耦合影响[J]. 吉林大学学报(工学版), 2020, 50(5): 1574-1583.
[4] 陈吉清,蓝庆生,兰凤崇,刘照麟. 基于轮胎力预判与拟合的轨迹跟踪控制[J]. 吉林大学学报(工学版), 2020, 50(5): 1565-1573.
[5] 沈哲,王毅刚,杨志刚,贺银芝. 风洞中未知声源漂移误差的逼近修正[J]. 吉林大学学报(工学版), 2020, 50(5): 1584-1589.
[6] 刘钊,程江琳,朱玉田,郑立辉. 轨道车辆垂向振动建模及运动关联分析[J]. 吉林大学学报(工学版), 2020, 50(5): 1600-1607.
[7] 李小雨,许男,仇韬,郭孔辉. 各向异性刚度对轮胎力学特性及车辆操纵性的影响[J]. 吉林大学学报(工学版), 2020, 50(2): 389-398.
[8] 陈鑫,王宁,沈传亮,冯晓,杨昌海. 后视镜造型对前侧窗气动噪声的影响[J]. 吉林大学学报(工学版), 2020, 50(2): 426-436.
[9] 李银平,靳添絮,刘立. 纯电动铲运机弓网续能系统设计与动态特性仿真[J]. 吉林大学学报(工学版), 2020, 50(2): 454-463.
[10] 赖晨光,王擎宇,胡博,文凯平,陈彦宇. 静气动弹性影响下带小翼汽车尾翼的设计与优化[J]. 吉林大学学报(工学版), 2020, 50(2): 399-407.
[11] 叶辉,刘畅,闫康康. 纤维增强复合材料在汽车覆盖件中的应用[J]. 吉林大学学报(工学版), 2020, 50(2): 417-425.
[12] 马芳武,梁鸿宇,赵颖,杨猛,蒲永锋. 内凹三角形负泊松比结构耐撞性多目标优化设计[J]. 吉林大学学报(工学版), 2020, 50(1): 29-35.
[13] 郭孔辉,黄世庆,吴海东. 适用于高频激励的面内轮胎动态模型[J]. 吉林大学学报(工学版), 2020, 50(1): 19-28.
[14] 王哲,谢怡,臧鹏飞,王耀. 基于极小值原理的燃料电池客车能量管理策略[J]. 吉林大学学报(工学版), 2020, 50(1): 36-43.
[15] 史文库,陈龙,张贵辉,陈志勇. 多级刚度双质量飞轮扭转特性建模与试验验证[J]. 吉林大学学报(工学版), 2020, 50(1): 44-52.
Viewed
Full text


Abstract

Cited
  Shared   
  Discussed   
No Suggested Reading articles found!
版权所有 © 《吉林大学学报(工学版)》编辑部
地址：长春市人民大街5988号　电话：+86-431-85095297　传真：+86-431-85094074　E-mail: xbgxb@jlu.edu.cn
本系统由北京玛格泰克科技发展有限公司设计开发