摘要
近年来,我国公路的建设日新月异,公路交通运输的水平得到了很大的发展。集装箱运输货车作为公路运输的主要工具,发挥着越来越重要的作用。为了提高运输效率,适应日益严格的节能减排政策以及促进环保,货车的空气动力学越来越受到人们的重视。
风洞试验和数值模拟是目前研究汽车空气动力学气动特性的主要研究方法。随着计算机技术的发展以及成本等因素的考虑,计算流体力学(Computational Fluid Dynamics,简称CFD)方法被越来越多的应用到汽车的开发过程中。本文介绍了汽车空气动力学发展历史和研究现状以及计算流体力学在汽车上的发展和应用状况。采用CFD方法对集装箱货车外流场进行研究,数值计算结果对于货车的设计与开发具有一定的指导意义。
首先,在集装箱货车三维CAD模型的基础上建立网格计算模型,运用CFD软件Fluent对货车在无侧风下行驶的外流场计算模拟。通过对集装箱货车外流场的流态进行详细分析研究,探讨了集装箱货车外流场的流动特征和气动阻力之间的关系,明确了产生气动阻力的主要原因,为后续减阻提供了参考依据。
接着,运用试验设计方法选取若干组试验点,基于响应面模型的基础上,建立起阻力系数和升力系数与导流罩几何参数之间的数学函数关系,利用优化算法对阻力系数函数得出最优解,与CFD数值模拟结果相比较,误差在5%以内。结合敏感性分析,分析出对整车气动阻力影响较为敏感的结构参数,对某款商用导流罩进行气动优化设计,对实车中的导流罩设计具有指导意义。
随后,讨论了三种横摆角下数值模拟汽车的方法,基于标模的基础上与风洞试验对比。经比较分析,本文选用方法3对集装箱货车进行横摆角下数值模拟。
最后,根据集装箱货车外流绕流特点,在集装箱前部加装涡流扰流装置,并探讨了该扰流装置几何参数对整车气动阻力的影响,为提升侧风环境中集装箱运输货车气动阻力特性水平提供了参考依据。
With the rapid progress on the construction of expressway in our country, the road transportation has great development.Nowadays,container semi-trailer truck, as the major tool in road transportation, plays an increasingly important role.To improve the efficiency of transportation, adapt the stricter policies on energy-saving and emission reduction, it is paid more and more attentions on the truck aerodynamics.
There are two major methods used in vehicle aerodynamics,which are wind tunnel test and numerical simulation. With the rapid development of computer technology and taking the cost into consideration, the method of Computational Fluid Dynamics (CFD) is more and more widely applied to the process of automobile's research and development.It is reviewed that the developing history and the current situation on road vehicle aerodynamics and CFD.The external field of the truck was simulated by the CFD method. The result of numerical simulation provides an instruction for the truck design and research.
At first, generate the grid computational model on the basis of three dimensional CAD model of the truck. Numerically simulate the external field of the truck without crosswind making use of the CFD software Fluent.The air flow in the external field of the truck is analytical researched in detail.The relationship between the flow characteristic of external flow field of the truck and the aerodynamic drag is on discussion.The reason why the drag was produced is clear. It provides references for the following work of drag reduction.
The next, select several experimental points using Design of Experiment (DOE), based on the Response Surface Method (RSM),the function relationship is established between coefficient of drag and lift and the five parameters,which reflect the cab roof fairing.The optimization solution can be obtained by algorithm.To compare with the result of CFD numerical simulation, the relative error is less than 5%.Combined with the sensitivity anlysis,analyze the structural parameters which are sisitive to the aerodynamic drag of the truck.Optimizing design for a kind of commercial cab roof fairing,it has the guiding sense to the cab roof fairing of the real truck.
Furthermore,three methods of simulating the truck in yaw angles were discussed. To compare with the result of wind tunnel test based on the standard model,method 3 was used for simulating the truck in yaw angles in this paper.
At last,based on the truck aerodynamic characteristic of external flow, the vortex trapped device added on the front of the trailer. The influence on the aerodynamic drag by the geometric parameters of that was discussed.It provides references that improving the characteristic of drag of the truck in crosswind.
引文
[1]谷正气主编.汽车空气动力学.第1版.北京:人民交通出版社,2005
[2]傅立敏.汽车空气动力学.第1版.北京:机械工业出版社,1998
[3]Riedler.Wissenschaftliche Automobilebewertung.Verl.Oldenburg,1911
[4]W.G.Aston.Body design and wind resistance.The Autocar.August,1911
[5]W.Klemperer.Investigation of the aerodynamics drag of Automobiles.Zeitshrift fur Flugtechnik Motorluftschiffahrt.Vol.13,1922
[6]P.Jaray.Der Stromlinienwagen-Eine neue Form der Automobile-Karosserie.Der Motorwagen.No.17,1922
[7]P.Jaray.Grundlagen fur die Berechnung des leistungsaufwandes von Kraftwagen. ATZ,Vol.37,1934
[8]A.Lange.Vergleichende Windkanalversuche a Fahrzeugmodellen.Berichte deuts-cher Kraftfahrzeugforschung im Auftrag des RVM.No.31,1937
[9]W.H.Hucho.Aerodynamics of Road Vehicle.Butterworth Co.Ltd,1987
[10]W.E.Lay.Is 50 miles per gallon possible with correct streamlining.SAE-Journal. Vol.32,1933
[11]W.Kamm.Lehrstuhl und Forshungsinstitut fur Kraftsfahrtwesen und Fahrzeut-motoren.Prospectus.Technische Hochshule.Stuttgart,1967
[12]W.Kamm and C.Schmid.Automobile Testing.Springer.Berlin,1938
[13]J.Andreau.Wind tunnel test and body design.J.Soc.Automot.Engrs.29,1931
[14]L.Romani.Les Essais aerodynamiques des voitures automobiles.maquettes et vehicles reel.Union Technique de L'Automobile et du Cycle.Paper No.11,1950
[15]R.G.S.White.A Rating Method for Assessing Vehicle Aerodynamic Drag Coeffi-cients.MIRA-Rep.No.1967/9
[16]A.J.Scibor-Rystki.Road Vehicle Aerodynamics.Pentch Press,1975
[17]Frank.Schenkel.The Origins of Drag and Lift Reductions on Automobiles with Front and Rear Spoilers.Society of Automotive Engineers,1978,1661-1670
[18]Colin H.Marks,Frank T. Buckley. The Effect of Tractor-Trailer Flow Interaction on the Drag and Distribution of Drag of Tractor-Trailer Trucks,SAE Paper 80-1403
[19]C.Berta, B.Bonis.Experimental Shape Research of Ideal Aerodynamic Charac-teristics for Industrial Vehicles.SAE Paper 801402
[20]Aerodynamic Evaluations of the 1980 F-Series Light and Medium Trucks and the 1978 C1-9000 Heavy Truck. SAE Paper 801405
[21]Van Tuan Tran.A Calculation Method for Estimating the Transient Wind Force and Moment Acting on a Vehicle. SAE Paper 910315
[22]Takuya Kataoka, Hiroshi China, Kunio Nakagawa etal.Numerical Simulation of Road Vehicle Aerodynamics and Effect of Aerodynamic Devices.SAE Paper 910597
[23]Toshio Kobayashi,Kozo Kitoh.A Review of CFD Methods and Their Application to Automobile Aerodynamics.SAE Paper 920338
[24]Akiyoshi Yamada, Shingo Ito.Computational Analysis of Flow Around a Simplified Vehicle-Like Body. SAE Paper 930293
[25]J.Williams,W. J.Quinlan, J.E.Hackett etal.A Calibration Study of CFD for Automotive Shapes and CD.SAE Paper 940323
[26]Tsutomu Fujimoto.Shape Study for a Low Air Resistance Air Deflector. SAE Paper 930301
[27]Tsutomu Fujimoto,Atsushi Niimura, Katsuharu Sakai.Shape Study for a Low Air-Resistance Air Deflector--The Second Report.SAE Paper 950633
[28]Robert J.Englar. Development of Pneumatic Aerodynamic Devices to Improve the Performance,Economics,and Safety of Heavy Vehicles.SAE Paper 2000-01-2208
[29]Robert J.Englar. Advanced Aerodynamic Devices to Improve the Performance, Economics,Handling and Safety of Heavy Vehicles.SAE Paper 2001-01-2072
[30]Robert J.Englar. Improved Pneumatic Aerodynamics for Drag Reduction, Fuel Economy, Safety and Stability Increase for Heavy Vehicles.SAE Paper 2005-01-3627
[31]Fred Browand, Charles Radovich.Mathieu Boivin.Fuel Savings By Means of Flaps Attached to the Base of a Trailer:Field Test Results.SAE Paper 2005-01-1016
[32]Charles A Radovich. Wind Tunnel Test of Cab Extender Incidence on Heavy Truck Aerodynamics.SAE Paper 2005-01-3527
[33]Kevin R. Cooper, Jason Leuschen.Model and Full-Scale Wind Tunnel Tests of Second-Generation Aerodynamic Fuel Saving Devices for Tractor-Trailers.SAE Paper 2005-01-3512
[34]Jason Leuschen, Kevin R.Cooper. Full-Scale Wind Tunnel Tests of Production and Prototype,Second-Generation Aerodynamic Drag-Reducing Devices for Tractor-Trailers.SAE Paper 2006-01-3456
[35]Paul J.Castellucci,Kambiz Salari.Computational Simulation of Tractor-Trailer Gap Flow with Drag-Reducing Aerodynamic Devices.SAE Paper 2005-01-3625
[36]Ronald E. Schoon, Fongloon Pan. Practical Devices for Heavy Truck Aerodynamic Drag Reduction.SAE Paper 2007-01-1781
[37]Ronald E.Schoon. On-road Evaluation of Devices to Reduce Heavy Truck Aerodynamic Drag. SAE Paper 2007-01-4294
[38]谷正气,莫志娇,姜乐华.汽车空气动力学发展概况[J].汽车科技,2002,(1):5-7
[39]马方武,马稚敏,傅立敏.红旗CA774型轿车空气动力性能的风洞试验研究.试验·测试,1991,10:17-21
[40]谷正气,秦德森,黄天泽.JT6120型大客车模型的气动力风洞试验研究.试验·测试,1994,1:32-34
[41]傅立敏.用空气动力学附加装置降低国产货车气动阻力措施的探讨.汽车工程,1994,16(3):144-148
[42]高利,高延龄.长头厢式货车加装导流罩的风洞和道路试验研究.中国公路学报,1995,8(3):50-58
[43]杜广生,杨绍华.厢式货车的气动附加装置及其减阻机理的分析.汽车技术,1994,5:23-28
[44]STEYR991邮政车导流罩空气阻力的风洞试验研究.陕西汽车,1997,1:13-17
[45]何忆斌.汽车车身气动造型优化研究及工程应用.[湖南大学博士学位论文].长沙:湖南大学,2008.
[46]李学武.某微车的气动特性分析与优化.[湖南大学硕士学位论文].长沙:湖南大学,2008
[47]谷正气,李学武,何忆斌.汽车减阻新方法.汽车工程,2008,30(5):441-443
[48]陈细军,谷正气等.PIV技术在汽车模型风洞中的应用.汽车工程,2009,31(2):170-174
[49]赵兰水,杜广生.厢式货车导流罩减阻节能的风洞实验研究.农业机械学报,2000,31(5):67-69
[50]刘连山,赵兰水,王肇杰等.厢式货车减阻方法的试验研究.试验·测试,2001,10:23-26
[51]王德昌.厢式货车附加装置减阻节能技术的数值模拟和试验研究.[山东大学硕士学位论文].济南:山东大学,2001
[52]赵兰水,孔祥雷.井字形格栅对厢式货车减小气动阻力的实验研究.兵工学报,2002,23(3):399-401
[53]马永坤.附加装置对厢式货车气动性能影响的试验研究与数值模拟.[山东大学 硕士学位论文].济南:山东大学,2007
[54]吴长鹏.导流罩对轻型厢式货车气动特性的影响.[吉林大学硕士学位论文].长春:吉林大学,2005
[55]刘畅,王靖宇,桑涛等.大型载货汽车驾驶室与货箱间隙对气动特性的影响.吉林大学学报(工学版),2007,37(2):280-285
[56]王靖宇,胡兴军,田华等.导流罩对轻型厢式货车气动特性影响的数值模拟.吉林大学学报(工学版),2008,38(1):12-16
[57]吴志刚,魏琪,加藤征三等.导流翼片的倾角和长度在降低大后壁车辆气动阻力中的作用.汽车工程,2003,25(6):634-637
[58]吴志刚,魏琪,加藤征三等.利用多个导流装置降低大后壁车辆气动阻力的试验研究.实验力学,2004,19(2):150-155
[59]傅强,金国栋.厢式货车的气动阻力及气动附加装置的应用.专用汽车,2002,2:3-6
[60]傅强.厢式货车降低气动阻力的研究.[华中科技大学硕士学位论文].武汉:华中科技大学,2002
[61]欧阳鸿武,唐艳君.EQ1092型载货车加装气动附加装置的模型风洞试验研究.试验·测试,2001,6:15-17
[62]赛伯里尔斯基著.汽车空气动力学.杨尊正,邹仲贤译.第1版.北京:人民交通出版社,1984
[63]杜广生.汽车空气动力学.北京:中国标准出版社,1999
[64]徐华舫.空气动力学基础.北京:北京航空学院出版社,1987
[65]傅德熏,马延文编著.计算流体力学.第1版.北京:高等教育出版社,2002
[66]吕明忠,高敦岳,傅立敏.计算机数值仿真在汽车外流场分析方面的应用研究.计算机辅助设计与图形学学报.2002.14(2):181-184
[67]张扬军,吕振华,徐石安.汽车空气动力学数值仿真研究进展.汽车工程,2001.23(2):82-91
[68]Diesel Guzzler. Engineers Propose Aerodynamic Improvements For Truck Trailers.http://www.sciencedaily.Com/videos/2008/1101-diesel_guzzler__money_saver.htm,2008-11-01
[69]陶文栓著.数值传热学.第1版.西安:西安交通大学出版社,1998
[70]吴军.汽车车身虚拟气动造型的研究:湖南大学硕士论文,1999
[71]傅立敏主编.汽车空气动力学数值计算.第1版.北京:北京理工大学出版社,2001,12-88
[72]吴军,钟志华,谷正气.汽车外流场数值仿真的进一步研究.机械工程学报,2003,39(9):110-113
[73]谷正气,吴军,姜乐华等.三维数值网格的生成及应用.数值计算与应用,2001.12(4)
[74]I.Demirdzic,M.Peric.Finite volume methods for heat, mass and momentum transfer in three-dimensional parabolic flows,Int.j.Num.Meth.Fluid,No.1990: 771-790
[75]S.V.Patanker, D.B.Spalding, A calculation processure for heat, mass and momentum transfer in three-dimensional parabolic flows.Int.J.Num.Meth.Fluid, 10:771-790,1990
[76]王福军编著.计算流体动力学分析.北京:清华大学出版社,2004
[77]H.K Versteeg,W.Malalasekera.An Introduction to Computational Fluid Dynamics:The Finite Volume Method.Wiley, New York,1995
[78]Marzio Piller, Enrico Nobile,J.Thomas,DNS study of turbulent transport at low Prandtl numbers in a channel flow. Journal of Fluid Mechanics,(458):419-441,2002
[79]J.G. Wissink. DNS of separating low Reynolds number flow in a turbine cascade with incoming wakes.International Journal of Heat and Fluid Flow,24(4):626-635,2003
[80]吴军.汽车外流场湍流模型与新概念车气动特性的研究.[湖南大学博士学位论文].长沙:湖南大学,2006
[81]Launder B E,Spalding D B.Lectures in Mathematical Models of Turbulence. London:Academic press,1972
[82]V.Yakhot, S.A.Orzag,Renormalization group analysis of turbulence:basic theory.Scient Comput.1:3-11,1986
[83]Shih T H,Liou W W,Shabbir A,Yang Z G,Zhu J.A Newκ-εEddy-Viscosity Model for High Reynolds Number Turbulent Flows.Compute Fluids, 1995,24(3):227-238
[84]吴允柱.汽车超车过程的气动特性研究.[吉林大学博士学位论文].吉林:吉林大学,2008
[85]宋振寰,朱炳哲.计算流体力学在模拟汽车外流场研究方面的发展状况.汽车科技.2002,1:5-7
[86]朱自强等.应用计算流体力学.北京:北京航空航天大学出版社,1998
[87]涂尚荣,张扬军等.汽车外流场仿真的复杂网格系统生成.汽车工程.2002,24(5):408-411
[88]FLUENT软件帮助.http://www.fuent.com
[89]R.H.Myers and D.C.Montgomery.Response Surface Methodology.New York, Wiley and Sons,1995:16-401
[90]G.E.P Box,J.S.Hunter.Multifactar Experimental Design for Exploring Response Surface.Annals of Mathematical Statistics.1957,28:195-241
[91]欧宏宇,贾士儒.SAS软件在微生物培养条件优化中的应用[J].天津轻工业学院学报.2001.36(1):14-17,27
[92]Douglas C.Montgomery著,汪仁官,陈荣昭译.实验设计与分析[M].北京:中国统计出版社.1998:612-626
[93]武藤真理著.汽车空气动力学.程正译.第1版.长春:吉林科学技术出版社,1989,106-120