气动附加装置降低厢式货车后体阻力

Experimental investigation on the aft-body drag reduction of the tractor-trailer truck by aerodynamic add-on device

在风洞中通过天平测力和静态压力传感器测压实验,研究了简易厢式货车模型安装背部隔栅气动附加装置后阻力特性和背部压力分布的变化。结果表明采用高度适当、布置合理的背部隔栅,可以使厢式货车后体侧缘的分离剪切层再附于隔板上并在隔板后缘再次分离。从而使厢式货车下游的分离尾涡区变窄,提高其背部压力,最终减小了厢式货车模型因后体分离引起的压差阻力。实验发现减阻效果最好的是采用的3横3竖形式、高度为50mm、距离厢式货车后体边缘30mm的隔栅,最大可以将模型的阻力减小7.19%。

The aerodynamic balance force and time-averaged wall pressure distribution measurements were carried out in the wind tunnel to investigate the aft-body drag reduction of the tractor-trailer truck model by an add-on device. When the scale and configuration of the back grid are proper to the truck model, the separated shear layers from the model trailing edges will reattach to the plate and separate again from the plate trailing edges, which results in the separation region width decrease downstream of the model, hence the back suction pressure of the model increases and the pressure drag of the model decreases. With the optimum scale and configuration of the back grid （three plates in both horizontal and vertical directions, 50ram high and 30mm far from the trailing edge of the model）,the drag of the track model in present study is reduced by 7.19%.