轿车空气动力学数值模拟及优化
摘要
由于高公路的发展、汽车车速的提高对汽车的操纵稳定性、安全性、舒适性提出了越来越高的要求，特别是由于世界能源危机，石油价格上涨，使改善汽车的燃料经济性成为汽车技术的重要课题。汽车空气动力特性对汽车的动力性、经济性和操纵稳定性有直接的影响。设计空气动力特性良好的汽车，是提高汽车动力性、经济性以及高速下的稳定性的重要途径。
风洞是传统的汽车空气动力特性的研究方法，它投资大、试验周期长，存在堵塞效应、地面效应等问题，且不能详细了解车辆外部流速、压力等参数的分布情况。所以仅采用风洞试验和路面测试技术研究汽车空气动力学，已不能满足更快速开发出更经济、安全、舒适的汽车的需要
随着计算机和计算机技术的迅速发展而蓬勃兴起的数值模拟方法为汽车空气动力性的研究开辟了新的途径。近年来，汽车空力学数值模拟发展迅速，其重要性也不断增加，应用范围不断扩大。在早期车型的开发中，应用数值模拟可为车身气动外形的初选提供依据，能方便、直观地了解汽车各部分的空气动力学状况以及尾部涡区结构及分布情况，初步计算出整车的气动阻力系数，为进一步细化设计提供依据，大大缩短了整车的开发周期，并节省了财力。而且，用数值模拟技术研究汽车流场对流体运动的认识在某种意义上比试验更深刻、更细致，不仅可以了解运动的结果，而且可以了解整体的与局部的细致过程，因此越来越得到人们的重视。
本文对项目轿车车身运用CFD软件FLUENT进行了数值模拟，并对结果进行了分析和优化。在汽车空气动力学数值模拟的实用化方面做了一些有益的尝试。
With the development of highway and the increasing of vehicle velocity, the require of control stability, security and inhabited comfort are higher than before. Especially with the lake of word energy source and the increasing of oil price, how to improve the economic character turns to the most important article. The vehicle's aerodynamic character directly affects the dynamic, economic and control stability characters. So design the vehicle with better aerodynamic is the key to all of the problems above.
Wind tunnel is the traditional method of aerodynamic research of vehicle, which is not suit to develop the fasten safer N more comfortable and economical vehicle, because long research period and much money is needed, and there are jam effect> road effect. Further more, the wind runnel method can not give the velocity of the flow and tress distributing of the vehicle.
The numerical simulation provides a new tool to the aerodynamic research of the vehicle, with the development of computer and compute technology. Of later years, the importance and the using field of numerical simulation are rapidly increasing. During the prophase of vehicle design, numerical simulation can conveniently and visually give the aerodynamic situation of every parts, approximately give the resistance quotiety (CD), prepares for the next design of the detail, which greatly reduce the period and money of vehicle development.
The result of calculation and optimization is discussed in the article, which make some useful attempts in aspect of practicality of the flow numerical simulation.
风洞是传统的汽车空气动力特性的研究方法，它投资大、试验周期长，存在堵塞效应、地面效应等问题，且不能详细了解车辆外部流速、压力等参数的分布情况。所以仅采用风洞试验和路面测试技术研究汽车空气动力学，已不能满足更快速开发出更经济、安全、舒适的汽车的需要
随着计算机和计算机技术的迅速发展而蓬勃兴起的数值模拟方法为汽车空气动力性的研究开辟了新的途径。近年来，汽车空力学数值模拟发展迅速，其重要性也不断增加，应用范围不断扩大。在早期车型的开发中，应用数值模拟可为车身气动外形的初选提供依据，能方便、直观地了解汽车各部分的空气动力学状况以及尾部涡区结构及分布情况，初步计算出整车的气动阻力系数，为进一步细化设计提供依据，大大缩短了整车的开发周期，并节省了财力。而且，用数值模拟技术研究汽车流场对流体运动的认识在某种意义上比试验更深刻、更细致，不仅可以了解运动的结果，而且可以了解整体的与局部的细致过程，因此越来越得到人们的重视。
本文对项目轿车车身运用CFD软件FLUENT进行了数值模拟，并对结果进行了分析和优化。在汽车空气动力学数值模拟的实用化方面做了一些有益的尝试。
With the development of highway and the increasing of vehicle velocity, the require of control stability, security and inhabited comfort are higher than before. Especially with the lake of word energy source and the increasing of oil price, how to improve the economic character turns to the most important article. The vehicle's aerodynamic character directly affects the dynamic, economic and control stability characters. So design the vehicle with better aerodynamic is the key to all of the problems above.
Wind tunnel is the traditional method of aerodynamic research of vehicle, which is not suit to develop the fasten safer N more comfortable and economical vehicle, because long research period and much money is needed, and there are jam effect> road effect. Further more, the wind runnel method can not give the velocity of the flow and tress distributing of the vehicle.
The numerical simulation provides a new tool to the aerodynamic research of the vehicle, with the development of computer and compute technology. Of later years, the importance and the using field of numerical simulation are rapidly increasing. During the prophase of vehicle design, numerical simulation can conveniently and visually give the aerodynamic situation of every parts, approximately give the resistance quotiety (CD), prepares for the next design of the detail, which greatly reduce the period and money of vehicle development.
The result of calculation and optimization is discussed in the article, which make some useful attempts in aspect of practicality of the flow numerical simulation.
引文
[1] 谷正气，汽车气动造型浅释，上海汽车，2000．4
[2] 章化麟，朱国林．汽车外流空气动力模拟．汽车工程．2000．1
[3] 黄向东．ICAS车身造型方法的风洞试验研究．华南理工大学学报．2000．6
[4] 胡强．从夏利2000看小型轿车车身设计的发展趋势．天津汽车．2001．1
[5] 肖超强．轿车车身智能化计算机辅助造型系统初探．华南理工大学学报．2000．1
[6] 孙永伶，孟嗣宗．桑塔纳2000型轿车外流场的有限元分析．上海汽车．2001．2
[7] 赵波．轻型客车车身的计算机辅助造型．上海汽车．2000．5
[8] 马力．国外轿车车身技术发展现状．世界汽车．2000．3
[9] 周廷美．车身外流场的半结构网格生成技术．武汉汽车工业大学学报．2000．6
[10] 傅立敏．汽车流场及尾部涡系数值模拟．吉林工业大学自然科学学报．2000．2
[11] 沈俊．CFD软件及其在汽车领域的应用．汽车研究与开发．2000．5
[12] 范士杰．CFD在汽车空气动力学设计中的应用．汽车技术．2000．10
[13] 吴立业．轿车外流场的数值计算和分析．江苏理工大学学报 2001．1
[14] 黄天泽．大客车车身．湖南大学出版社．1998
[15] 邬晴晖．国内外车身设计技术的差距．汽车技术．1999．8
[16] 兰凤崇．汽车车身计算机辅助造型设计．吉林科学技术出版社．1992．6
[17] 黄天泽．汽车车身机构与设计．机械工业出版社．1997．10
[18] 陈熙．车身质量控制．上海汽车．2000．2
[19] 傅立敏．轿车三维分离流动特性的研究．汽车工程．1998．2
[20] 胡树华．我国轿车业的世纪发展战略思考．上海汽车．2000．8
[21] 王志鲲．基于计算流体力学软件的汽车风洞流场及其边界层控制的研究 上海汽车．2001．4
[22] 谷正气．轿车外流场的三维计算机模拟．汽车工程．2000．5
[23] 张扬军．汽车空气动力学数值仿真研究进展．汽车工程．2001．2
[24] 常思勤．计算机流体力学进展及其在汽车设计中的应用．武汉汽车工业大学学报．1997．2-15
[25] 傅立敏．流结构的研究．汽车工程．1996．6
[26] 朱自强．应用计算流体力学．北京航空航天大学出版社．1998
[27] 朱国林等．小轿车绕流场数值计算和分析．空气动力学学报．1998．16(1)
[28] 林程等．轿车外表面计算机建模方法的研究．汽车技术．1998．10
[29] 常思勤．CFD应用与车辆空气动力学特性的研究．武汉汽车工业大学学报．1999．1
[30] 青本清平．汽车尾部不稳定涡流结构的数值分析．自动车技术会论文集．1998．29(2)
[31] 吴亚良．现代轿车车身设计．上海科学技术出版社．1999．3
[32] A．J．赛伯 里尔斯基．汽车空气动力学．人民交通出版社．1984．4
[33] 陈矛章．粘性流体动力学基础．北京：高等教育出版社，1993
[34] Aoki K etal. Finite—Volume Simulation Of 3D Vertical Flow—Fields About Road Vehicles with Various After Body Configuration. SAE 931896
[35] Jameson. Re—Engineering the Design Process Through Computation. Journal of Aircraft, 1999(1)
[36] Pla L. CFD as a Tool in Styling Vehicles. Second CFDS international User Conference, 1994. 9
[37] Dhaubhadel M. CFD Applications in the Automotive Industry. Journal of Fluids Engineering, Transactions of the ASME, 1996(9)
[38] Validation of CFD Codes for predicting aeodynamic performance. Automotive Engineering SPECIAL FEATURE. October / November, 1992
[39] Fu Limin. Research of Car's 3D Seperating Flow Characteristics. FISITA World Automotive Congress, 1998
[40] MatsunagaKEIJI, etal. Finite Diffrence Simulation of 3D Vertical Flows Past Road Vehicle. SAE 920339
[41] Kuethe A M, Chow C Y. Foundations Of Aerodynamic. John Wiley, New York, 1976
[42] Sch61ichting H, Truckenbrodt E. Aerodynamic Of the Airplane. New York, MC Graw-Hil, 1979
[43] DA Costa A L. Application Of Computational Aerodynamic Methods To the Design and Analysis Of Transports Aircraft. ICAS Paper. Eleventh Congress Of the International Council Of the Aeronautical Science, Lisbon, Portugal, 10-16, Sept., 1978
[44] Rubdert P E, Saaris G R. Review and Evaluation Of a Three—Dimensional
Lifting Potential FlOW Analysis Method for Arbitrary Configuration. AIAA Paper 72-188, 1972
[45] Kraus W. Panel Methods in Aerodynamics. Numerical Methods in Fluid Dynamics. Hemisphere Publication CO., 1978
[46] Ahmed S R, Hucho W-H. The Calculation Of the Flow Field Past a Van with the Aid Of a Panel Method. SAE Paper 770390
[47] Buchheim R, Rohe H, Wüstenbero H. Experiences with Computational Fluid Mechanics in Automobile Aerodynamics, 2nd Intern. ATA Symposium, Use Of Supercomputers in the European Automotive Industry. Turin, Italy, 1988
[48] Hucho W-H, Sovran G. Aerodynamics Of Road Vehicles, Annual Review Of Fluid Mechanics, 1993;25
[2] 章化麟，朱国林．汽车外流空气动力模拟．汽车工程．2000．1
[3] 黄向东．ICAS车身造型方法的风洞试验研究．华南理工大学学报．2000．6
[4] 胡强．从夏利2000看小型轿车车身设计的发展趋势．天津汽车．2001．1
[5] 肖超强．轿车车身智能化计算机辅助造型系统初探．华南理工大学学报．2000．1
[6] 孙永伶，孟嗣宗．桑塔纳2000型轿车外流场的有限元分析．上海汽车．2001．2
[7] 赵波．轻型客车车身的计算机辅助造型．上海汽车．2000．5
[8] 马力．国外轿车车身技术发展现状．世界汽车．2000．3
[9] 周廷美．车身外流场的半结构网格生成技术．武汉汽车工业大学学报．2000．6
[10] 傅立敏．汽车流场及尾部涡系数值模拟．吉林工业大学自然科学学报．2000．2
[11] 沈俊．CFD软件及其在汽车领域的应用．汽车研究与开发．2000．5
[12] 范士杰．CFD在汽车空气动力学设计中的应用．汽车技术．2000．10
[13] 吴立业．轿车外流场的数值计算和分析．江苏理工大学学报 2001．1
[14] 黄天泽．大客车车身．湖南大学出版社．1998
[15] 邬晴晖．国内外车身设计技术的差距．汽车技术．1999．8
[16] 兰凤崇．汽车车身计算机辅助造型设计．吉林科学技术出版社．1992．6
[17] 黄天泽．汽车车身机构与设计．机械工业出版社．1997．10
[18] 陈熙．车身质量控制．上海汽车．2000．2
[19] 傅立敏．轿车三维分离流动特性的研究．汽车工程．1998．2
[20] 胡树华．我国轿车业的世纪发展战略思考．上海汽车．2000．8
[21] 王志鲲．基于计算流体力学软件的汽车风洞流场及其边界层控制的研究 上海汽车．2001．4
[22] 谷正气．轿车外流场的三维计算机模拟．汽车工程．2000．5
[23] 张扬军．汽车空气动力学数值仿真研究进展．汽车工程．2001．2
[24] 常思勤．计算机流体力学进展及其在汽车设计中的应用．武汉汽车工业大学学报．1997．2-15
[25] 傅立敏．流结构的研究．汽车工程．1996．6
[26] 朱自强．应用计算流体力学．北京航空航天大学出版社．1998
[27] 朱国林等．小轿车绕流场数值计算和分析．空气动力学学报．1998．16(1)
[28] 林程等．轿车外表面计算机建模方法的研究．汽车技术．1998．10
[29] 常思勤．CFD应用与车辆空气动力学特性的研究．武汉汽车工业大学学报．1999．1
[30] 青本清平．汽车尾部不稳定涡流结构的数值分析．自动车技术会论文集．1998．29(2)
[31] 吴亚良．现代轿车车身设计．上海科学技术出版社．1999．3
[32] A．J．赛伯 里尔斯基．汽车空气动力学．人民交通出版社．1984．4
[33] 陈矛章．粘性流体动力学基础．北京：高等教育出版社，1993
[34] Aoki K etal. Finite—Volume Simulation Of 3D Vertical Flow—Fields About Road Vehicles with Various After Body Configuration. SAE 931896
[35] Jameson. Re—Engineering the Design Process Through Computation. Journal of Aircraft, 1999(1)
[36] Pla L. CFD as a Tool in Styling Vehicles. Second CFDS international User Conference, 1994. 9
[37] Dhaubhadel M. CFD Applications in the Automotive Industry. Journal of Fluids Engineering, Transactions of the ASME, 1996(9)
[38] Validation of CFD Codes for predicting aeodynamic performance. Automotive Engineering SPECIAL FEATURE. October / November, 1992
[39] Fu Limin. Research of Car's 3D Seperating Flow Characteristics. FISITA World Automotive Congress, 1998
[40] MatsunagaKEIJI, etal. Finite Diffrence Simulation of 3D Vertical Flows Past Road Vehicle. SAE 920339
[41] Kuethe A M, Chow C Y. Foundations Of Aerodynamic. John Wiley, New York, 1976
[42] Sch61ichting H, Truckenbrodt E. Aerodynamic Of the Airplane. New York, MC Graw-Hil, 1979
[43] DA Costa A L. Application Of Computational Aerodynamic Methods To the Design and Analysis Of Transports Aircraft. ICAS Paper. Eleventh Congress Of the International Council Of the Aeronautical Science, Lisbon, Portugal, 10-16, Sept., 1978
[44] Rubdert P E, Saaris G R. Review and Evaluation Of a Three—Dimensional
Lifting Potential FlOW Analysis Method for Arbitrary Configuration. AIAA Paper 72-188, 1972
[45] Kraus W. Panel Methods in Aerodynamics. Numerical Methods in Fluid Dynamics. Hemisphere Publication CO., 1978
[46] Ahmed S R, Hucho W-H. The Calculation Of the Flow Field Past a Van with the Aid Of a Panel Method. SAE Paper 770390
[47] Buchheim R, Rohe H, Wüstenbero H. Experiences with Computational Fluid Mechanics in Automobile Aerodynamics, 2nd Intern. ATA Symposium, Use Of Supercomputers in the European Automotive Industry. Turin, Italy, 1988
[48] Hucho W-H, Sovran G. Aerodynamics Of Road Vehicles, Annual Review Of Fluid Mechanics, 1993;25