车轮宽度对轿车风阻的影响

Influence of Wheel Width on Vehicle Aerodynamic Drag

摘要:

针对某三厢轿车，采用计算流体动力学(CFD)数值计算方法，研究车轮宽度对整车气动性能的影响.通过综合分析不同宽度孤立车轮周围的流场结构变化及具有不同宽度车轮的整车周围流场的结构特性，得到结论：车轮宽度每减小5%，单车轮模型气动阻力约减小9.2%，整车模型气动阻力约减小2%.这是因为减小车轮宽度可以减小车轮两侧的气流分离，缩小尾部涡流区域，降低车轮及汽车尾部湍流强度，从而有助于降低车轮及整车气动阻力.

Abstract:

The computational fluid dynamics method was applied to an investigation of the influence of wheel width on vehicle aerodynamic performance for a general sedan car. After a comprehensive analysis and comparison of the changes in flow structure of isolated wheels and full scaled vehicle models with different wheel widths, the conclusion can be drown that the aerodynamic drag of isolated wheel decreases approximately by 9.2% while the aerodynamic drag of whole car model decreases by about 2% when the wheel width reduces by every 5%. This is due to the reason that the reduction of wheel width can effectively decrease the flow separation beside the wheel and then the vortex zone in the wake, besides, it can also lower the turbulence intensity in the rear ended area of the isolated wheel as well as the whole car model, which will help to reduce aerodynamic drag of the given models.