车身非光滑表面凹坑排布对气动性能的影响

受仿生学非光滑旋成体减阻启发，以SAE(美国机动车工程师协会)标准模型为研究对象，采用CFD(计算流体力学)数值模拟方法，在SAE模型顶部布置不同排布形式和不同排布密度的凹坑单元，研究其对车身气动性能的影响.通过比较各模型的尾流、气流速度、压力场、湍流动能等流场性能指标，分析非光滑表面减阻机理以及造成各模型流场性质差异的原因.计算结果显示:当凹坑型非光滑单元以矩形排布时模型具有最小的气动阻力，且气动阻力随着凹坑密度的增加而减小，减阻率最高达到4.1%.

Effects of Non-Smooth Surface Dimple Configuration on Vehicle Body Aerodynamic Characteristics

According to the idea of bionic non-smooth revolution bodies, the SAE (Society of Automobile Engineers) standard model was selected as the object of study, and the computational fluid dynamics (CFD) method was used to investigate the effects of different non-smooth surface dimple array forms and densities on the aerodynamic performance of vehicle bodies. Through comparison of such flow field performance indicators as wake flow, airflow velocity, pressure field and turbulence kinetic energy between various models, the drag reduction mechanism of the dimpled non-smooth surface and the reasons for the difference of flow field properties between those models were analyzed. The results show that the minimum aerodynamic drag occurs when the dimple units are arranged in a rectangular configuration, and the aerodynamic drag decreases along with the longitudinal dimple distribution density, attaining the highest drag reduction ratio up to 4.1%.