甩挂运输对重型载货汽车气动性能的影响

甩挂运输已发展成为国家运输业节能减排的重要着力点，牵弓I车与不同挂车的组合方式对整车气动性能的影响不容忽视．以某重型载货汽车为研究对象，运用计算流体力学（Computational Fluid Dynamics，CFD）方法，分析了甩挂运输中不同主挂车间隙对整车流场结构的影响；利用正交试验，研究了间隙、货箱高度与导流罩角度三者对整车气动阻力系数的影响．研究结果表明，间隙长度对无导流罩整车与带导流罩整车的气动特性影响各不相同，正交试验可有效分析不同因素对气动阻力系数的影响程度，优化模型与原始模型相比，减阻达2．5％．

Influence of drop-and-pull transport on heavy-duty truck aerodynamic performance

Drop-and-pull transport has been an important task of national road-way transport energy saving and emission reduction strategy, and the influences of combinations between tractor and trailer on aerodynamic performance should not be ignored. By the use of computational fluid dynamics （CFD）, the influences of different gaps between a tractor equipped with a wind deflector or not and a trailer have been evaluated, and the effects of gap, height of container and angle of deflector on aerodynamic drag coefficient of truck are studied using orthogonal experiment design. The results show that the gaps have different effects on the truck equipped with a wind deflector or not, and drag coefficients show different trends. Through orthogonal experiment, the influences of different factors on drag coefficients are analyzed efficiently. Compare with original model, the optimized model can reduce its drag coefficient by 2.5% at most.