Abstract: With the increase of domestic automotive full-scale wind tunnel resources, the wide application of road load (wind tunnel method) in Limits and Measurement Methods for Emissions from Light-duty Vehicles (China 6) (GB18352.6–2016) has become possible. The test state of the vehicle in the traditional wind tunnel method is not consistent with the actual road driving state, which leads to a certain deviation between the test result of the wind tunnel method and the actual road load, and the test cost is high and the efficiency is low. In order to solve these shortcomings of the traditional wind tunnel method, this paper simulates the driving state of the vehicle under the actual road in the aerodynamic-acoustic wind tunnel, and directly corrects the aerodynamic resistance and roll resistance at each speed, and finally obtains the road load of the vehicle. A comparison between the new wind tunnel method and road coast-down results indicates that the resistance results of the two methods are consistent and the difference is small, and the worldwide light vehicles test cycle (WLTC) energy difference is far less than the standard ±5%, which proves the efficiency and effectiveness of the method, and can be used as one of the alternative methods for coast-down, providing support for the subsequent practical application and standard research of the wind tunnel method for new energy vehicles.

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

摘要： 随着国内汽车全尺寸风洞资源的增加，《轻型汽车污染物排放限值及测量方法（中国第 六阶段）》（GB18352.6－2016）中关于道路载荷（风洞法）的广泛应用成为可能。传统风洞法 测试中车辆测试状态和在实际道路行驶状态并不一致，进而导致风洞法测试结果和实际道路 载荷存在一定偏差，且测试成本较高，效率较低。为解决传统风洞法的诸多缺点，文章通过 在气动声学风洞中模拟车辆实际道路下的行驶状态，对各速度下的气动阻力和滚阻直接进行 修正，最后得到车辆道路载荷。对比新的风洞法和道路滑行结果表明：两者阻力结果趋势一 致，差异较小，全球统一轻型车辆测试循环（WLTC）工况循环能量差远小于标准规定的±5%， 证明该方法的高效性和有效性，可作为道路滑行的替代方法之一，为后续新能源车辆风洞法 的实际应用和标准研究提供支撑。

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