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

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