摘要
对复杂车身底部流动特性进行分析和改进,以达到降低车身阻力和提高车辆行驶稳定性的目的,以某轿车模型为研究对象,对汽车底部外形进行增加密封盖板、凸唇状扰流板以及布置凹坑型非光滑表面等组合改型设计,研究改进设计对汽车空气动力特性的影响,并对产生影响的原因进行分析。模拟计算结果表明:通过组合改进设计,增大底部气流速度,改善底部气流分布形式,在凹坑底部形成类似球形的小涡,将气固表面滑动摩擦阻力转化为滚动摩擦阻力。气动升力系数减小73.8%,气动阻力系数减小7.4%,达到了既大幅降低升力系数又减小阻力系数的目的,可为汽车底部外形设计和改型提供参考。
The complex underbody flow characteristics of the automobile were analyzed and improved in order to reduce the aerodynamic drag and improve the stability of the automobile on travel. Taking a car model as research object, different underbody shapes were designed through increasing a sealed cover and a convex lip-shaped spoiler and arranging pit unsmooth surface on the bottom of the car. The influences of the improved design on automobile aerodynamic characteristic were researched and the reasons were analyzed. The results show that the velocity and distribution of underbody airflow are separately increased and improved through resultant improved design. Some small ball-like vortices are formed inside pit unsmooth surface which turns sliding friction force into rolling friction force on the gas-solid surface. The coefficient of aerodynamic lift decreases by 73.8% and the coefficient of aerodynamic drag decreases by 7.4%, which has achieved the targets of lowering the coefficients of aerodynamic lift dramatically and decreasing the coefficients of aerodynamic drag as well. Therefore, the design will provide reference for underbody shape design.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第10期4063-4068,共6页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51375155)
湖南省自然科学基金资助项目(12JJ3041)
关键词
车身
气动升力
气动阻力
底部流场
改进设计
automobile body
aerodynamic lift
aerodynamic drag
underbody flow flied
improved design
