侧向风及车间距对尾随行驶货车的影响

Effect of lateral wind and longitudinal spacing on the two trucks in tandem

车辆进行尾随行驶时其外流场会受到侧向风及车间距变化的影响,为此本文参照沃尔沃某型号货车,按照1∶1的比例建立了货车仿真模型,利用XFlow作为数值仿真软件,分别对车间距离变化范围为0~30m及侧风来流角度变化范围为0°~20°的情况进行了数值仿真,并从汽车风阻系数变化及节油效果两个方面进行了具体分析。结果显示,在没有侧向风时后车平均节油率为22.96%,当侧向风来流角度为20°时,后车的平均节油率仅为7.41%,表明侧向风的存在大大降低了货车尾随行驶的节油效果。

The external flow-field around trucks would be affected by the lateral wind and their longitudinal spacing change when the trucks travel in tandem.In order to analyze the influence,in reference to the Volvo truck,a simulation truck model with scale of 1：1 was established.XFlow software was used as the numerical simulation tool.The longitudinal spacing ranged from 0mto 30 m,and yaw angle of the wind variation range was 0to 20 degree.The simulation results were analyzed from two aspects,drag coefficient change and fuel-saving rate.The results show that the average fuel-saving rate of the following truck is about 22.96% without lateral wind.While at yaw angle of 20 degree of the lateral wind,the fuel-saving rate is only about 7.41%.This suggests that the lateral wind has great influence on the fuel-saving of the trucks traveling in tandem.