Abstract: With the development of domestic full-size automobile wind tunnel technology and new energy vehicle technology, road load (wind tunnel method) in Light Vehicle Pollutant Emission Limits and Measurement Methods (China's Sixth Stage) (GB 18352.6－2016) is gradually being used for vehicle road load measurement. However, there is a deviation between the fixed posture of the vehicle in the wind tunnel test and the actual road driving posture, and the vehicle needs to switch between the wind tunnel laboratory and the drum laboratory, which is inefficient. In order to verify the effectiveness of the method of measuring vehicle road load directly in the aerodynamic-acoustic wind tunnel, this paper directly simulates the vehicle fixed posture under the real road in the aerodynamic-acoustic wind tunnel, and simultaneously measures the wind resistance and roll resistance of the vehicle in a test, and directly obtains the road load of the vehicle. The comparison of road load measured directly by wind tunnel and coastdown method shows that, the overall trend of the road load resistance curve measured by the two methods is the same, and the difference is small. the difference of the cyclic energy in each speed segment of world light vehicle test cycle (WLTC) is small. The difference of total circulating energy is also small, and the total cycle energy difference is less than ±5% specified in the standard, which proves the effectiveness of this method and provides a new test method for the subsequent road load testing and research of new energy vehicles.

Key words: aerodynamic-acoustic wind tunnel; road load (wind tunnel method); running resistance; coastdown

摘要： 随着国内全尺寸汽车风洞技术和新能源汽车技术的发展，《轻型汽车污染物排放限值及 测量方法（中国第六阶段）》（GB 18352.6－2016）中道路载荷（风洞法）正逐渐用于整车道 路载荷测量，但风洞测试中车辆的固定姿态和实际道路行驶姿态存在偏差，车辆需在风洞实 验室和转鼓实验室之间切换，效率较低。为验证气动声学风洞中直接测定车辆道路载荷方法 的有效性，文章通过在气动声学风洞中直接模拟车辆在真实道路下的行驶姿态，在一次试验 中同时对车辆的风阻和滚阻进行测量，直接得到车辆的道路载荷。对比道路滑行和风洞直接 测定的道路载荷，结果表明，两种方法测得的道路载荷阻力曲线总体趋势一致，差异较小， 全球统一轻型车辆测试循环（WLTC）各个速度段循环能量和总循环能量差异都较小，总循环 能量差小于标准规定的±5%，证明该方法的有效性，为后续新能源车辆的道路载荷测试和研 究提供一个新的测试方法。

关键词: 气动声学风洞；道路载荷（风洞法）；道路行驶阻力；道路滑行