中文摘要：

为了优化重型卡车的风阻系数，研究了卡车尾部扰流翼和驾驶室与货箱连接间隙调整对阻力系数降低的作用，并考虑了无风条件下实际行驶过程中地面与车体相对运动和车轮受压形状改变对阻力的影响。运用低速风洞试验与商业软件FLUENT，在不同减阻附件安装情况下，分析了美国标准Class8卡车的车身绕流特性与阻力系数的变化。研究结果表明：车身连接处与尾部扰流翼减阻附件的安装可以减弱货箱前部气流分离和尾部涡量，从而降低卡车阻力系数。在90km·h^-1经济速度下，安装2组减阻附件后的卡车阻力系数最高可降低16．2％，最小值可达到0．4854。

英文摘要：

To optimize the drag coefficient of heavy truck, the effect of rear spoilers and linking seals between cab and packing case was tested, in which the relative motion between truck and road and the pressed deformations of tires in real running under windless conditions were considered. The numerical simulation using commercial computational fluid dynamics software FLUENT and low-speed wind tunnel experiments were carried out to investigate the airflow characteristics around the US standard Class 8 truck and the drag coefficients of truck with different add-on devices. Analysis result indicates that by attaching the proper add-on devices, such as linking seals and rear spoilers, the rear vortices and front airflow sparation of packing case reduce, which results in the significant reduction of drag coefficient. At commercial speed of 90 km· h^-1 , drag coefficient decreases by 16.2% and its minimum value is 0. 485 4. 6 tabs, 16 figs, 13 refs.