汽车底部结构对气动特性影响的数值仿真与实验研究  

Numerical Simulation and Experimental Research of Influence of Underbody Structure on Aerodynamic Characteristics

作　　者：袁志群[1,2] 谷正气[1,3] 何忆斌[1] 汪怡平[1] 陈细军[1] 

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082 [2]厦门理工学院机械工程系,厦门361024 [3]湖南工业大学,株洲412008

出　　处：《系统仿真学报》2010年第8期1832-1836,1841,共6页Journal of System Simulation

基　　金：国家自然科学基金(50975083);国家863计划资助项目(2007AA04Z122);湖南大学汽车车身先进设计制造国家重点实验室自主研究课题(60870001);教育部长江学者与创新团队发展计划(531105050037);湖南省科技计划重点项目(06FJ2001)

摘　　要：以降低车身阻力和获得汽车底部流动最佳化外形为目的,应用计算流体动力学方法对汽车底部空气流动特性进行数值仿真,详细描述了汽车底部以及尾部的空气流动机理。计算结果表明:底部结构对汽车底部空气流动特性和尾涡特性有明显影响,是整车气动特性的关键组成部分,使气动阻力系数增加0.0523,气动升力系数增加0.1495;进一步分析得出,存在一个最佳的尾气排放速度使得气动阻力系数最大能够下降0.0136。汽车模型的风洞实验和PIV实验验证了该计算方法的准确性,计算分析结果为汽车底部设计与改进提供了参考数据。In order to reduce the aerodynamic drag and obtain the optimal underbody airflow shape,the CFD method was applied to study the airflow Characteristics of underbody and analyze the airflow principles of underbody and wake.The result shows that the influence of underbody structure is notable on airflow characteristics of underbody and wake characteristics.Underbody structure is one of the critical components to aerodynamic characteristics of car,which makes the drag coefficient increase 0.0523 and the lift coefficient increase 0.1495 as well.Further analysis indicates that the largest reduction of drag coefficient is 0.0136 because of the optimal velocity of exhaust.The simulation results agree well with the test data in the wind tunnel and PIV test date,which indicates that numerical simulation for automotive aerodynamics characteristics is feasible.Analysis of the results can give a beneficial basis for underbody designing.

关 键 词：空气流动特性 数值仿真 底部结构 阻力系数 升力系数 风洞实验 PIV 

分 类 号：U461.1[机械工程—车辆工程] TP391.9[交通运输工程—载运工具运用工程]