【作者】 彭亚美；

【导师】 谷正气；

【作者基本信息】 湖南大学 ， 车辆工程， 2010， 硕士

【摘要】 汽车气动特性对汽车的动力性、燃油经济性、操纵稳定性、舒适性和安全性有着非常大的影响。通过汽车气动特性研究来降低汽车气动阻力,不仅可以提高汽车的动力性,而且还可以提高发动机燃烧效率,改善汽车的燃油经济性。另外,汽车在高速行驶时的侧风稳定性是汽车安全性的重要指标之一。因此,开展汽车气动特性研究对提高汽车的安全性以及汽车节能减排有着非常重要的意义。汽车风洞试验是汽车气动特性研究的重要手段,本文以湖南大学HD-2风洞为试验平台,开展中气轿车气动特性模型风洞试验研究。首先,阐述了汽车风洞的类型及构造、汽车风洞试验技术要求以及汽车风洞试验洞壁干扰的修正方法等汽车风洞试验理论,并较详细地介绍了测试设备、仪器以及它们的原理与使用方法。其次,测量了中气模型的气动力及力矩,分析该模型的气动特性以及后视镜对其阻力系数、升力系数的影响；采用粒子图像测速(PIV)系统定量地测量中气模型纵对面的流场,分析中气模型尾部的涡量特性与湍动能特性；同时,本文还采用电子压力扫描阀系统测量中气模型纵对面表面压强分布,分析中气模型纵对面表面平均压力系数与脉动压力系数的分布特性,及其对该模型气动性能的影响。汽车队列行驶是智能交通系统研究的热点之一,本文最后还研究了队列行驶间距对中气轿车气动特性的影响,为队列行驶间距的确定提供试验依据。本文的研究成果对汽车气动性能的评估与优化有较大的指导意义,并有助于理解汽车气动力产生及作用的机理。更多还原

【Abstract】 The power performance, fuel efficiency, handling stability, comfort and safety of an automoblie are significantly affected by its aerodynamic characteristics. By study on aerodynamic characteristics of automobile to reduce the aerodynamic drag, can not only improve power performance, but also can improve engine’s combustion efficiency and improve fuel economy. In addition, crosswind stability is one of important indicator of safety when automobile at high speeds. Therefore, carry out the research on aerodynamic characteristics of automobile has a very great significance to improve the safety of automobile and reduction of automotive exhaust emissions.Wind tunnel test is the major method which is used by the study of aerodynamic characteristics of automobile. In this paper, based on the test which is carried by HD-2 wind tunnel in Hunan University, do research on the aerodynamic characteristic of Zhongqi car model in the wind tunnel. To begin with, demonstrate the theory about wind tunnel test, such as types and configuration of wind tunnel, technical requirements for the wind tunnel test, the correct method of wall interference. Describe the test equipment, instruments, principle and instruction of that in detail. Then, measure the aerodynamic force and moment of the model, analyze the influence of aerodynamic characteristics of the model and rear mirror on drag coefficient and lift coefficient; quantitatively measure the model external flow field in symmetry by Particle Image Velocimetry (PIV), the characteristics of vortices and turbulence kinetic energy in the rear part of the model is analyzed; meanwhile, measure the pressure distribution of the model in symmetry by Electronic Pressure Scanner Valve(EPSV). Analyze the distribution characteristics of the coefficients of surface pressure and fluctuation pressure on the model in symmetry, and study the influence of the result on the aerodynamic characteristics of the car.Platoon is one of the hotspots in study of Intelligent Transportation System. Finally, this paper study the influence of platoon longitudinal spacing on the aerodynamic characteristics of Zhongqi car, and provide experimental basis for determine the longitudinal spacing.The results of this paper are significant to evaluate and optimize the aerodynamic capability of automobile, and help understand the mechanism of the generation and action of aerodynamic force.更多还原