车尾造型对凹坑型非光滑车身气动减阻的影响

摘要

将凹坑型非光滑表面布置在MIRA直背式、斜背式、阶梯背式3种模型的尾部，分析了3种不同车型的尾流结构，研究不同的汽车尾部造型对非光滑车身气动减阻的影响。通过对模型外部流场的数值计算，比较光滑模型和非光滑模型尾部流场、压力、湍动能等参数，对比不同尾部造型非光滑表面流场差异，分析非光滑表面气动减阻的机理，解释不同车尾造型减阻率差异的原因，为进一步研究车身非光滑表面气动减阻效果提供理论依据。%Pit-type non-smooth surfaces are adopted for the three types of rear end ( squareback, fastback and notchback) of MIRA model and their wake structures are analyzed to study the effects of different rear-end shapes on the aerodynamic drag reduction of non-smooth car body. Through the numerical calculation of external flow field of models, the flow field, pressure, turbulent kinetic energy and other parameters of rear end of both smooth and non-smooth models are compared. The flow field differences of non-smooth surface of different tail shapes are also compared, the mechanism of aerodynamic drag reduction of non-smooth car body is analyzed, and the reasons for the differences in drag reduction rates of different car tail shapes are explained, providing a theoreti-cal basis for the further research on the aerodynamic drag reduction of non-smooth car body.