车身非光滑表面位置对气动性能的影响

Influence of non-smooth surface decorated position effects on aerodynamic characteristic

以SAE(美国机动车工程师学会)模型为研究对象,采用计算流体力学数值模拟方法研究非光滑表面布置位置对车身气动性能的影响.通过对钝体模型的不同位置(侧部、底部、顶部、尾部)布置凹坑型非光滑表面,计算钝体模型的空气阻力系数,比较光滑表面与非光滑表面速度矢量、压力以及湍动能,分析了非光滑表面气动减阻机理和减阻效果差异的原因,根据分析结果得到在模型的侧部、顶部、尾部和底部布置非光滑表面均能起到减阻作用,尾部非光滑表面的减阻效果最明显,减阻率达到5.73%.

Based on the SAE （Society of Automotive Engineers）model,the influence that the differ-ent position of non-smooth surface decorating affects on the aerodynamic characteristic was studied u-sing computational fluid dynamics numerical simulation method.By decorating pit type non-smooth surface on different position of the blunt car model （sidepiece,bottom,top,and rear）,air drag coeffi-cient,comparing velocity vector,pressure and turbulent kinetic energy of non-smooth surface with the smooth surface were calculated,and the reducing drag mechanism of non-smooth surface and the rea-sons for the differences were analyzed.The result shows non-smooth surfaces at different locations have a good effect on drag reduction,and the tail is the most obvious,with the drag reduction effect of 5 .73%.