The Guangzhou Automotive Group Co. Aerodynamic, Acoustic, and Thermal Wind Tunnel

The Guangzhou Automotive Group Co., Ltd (GAC Group) wind tunnel, located in Guangzhou, China, is a state-of-the-art facility that uniquely integrates world-class aerodynamic flow quality, acoustic capability, and thermal conditions into a single system for the development of passenger vehicles. This closed return, ¾ open jet wind tunnel features a nozzle with a cross-section of 20 m² and a 2.5 MW fan, capable of delivering a maximum wind speed of 200 km/h. The wind tunnel is equipped with a ±90° turntable, a boundary layer control system, and a 5-belt moving ground plane system for aerodynamic tests. Comprehensive acoustic treatments in the test section and throughout the wind tunnel circuit establish a hemi-anechoic test environment with minimal background noise levels for acoustic tests. For thermal tests, the wind tunnel includes a 4-wheel chassis dynamometer system downstream of the turntable, with temperature control ranging from 20°C to 60°C and humidity control between 15% and 90% with the maximum dew point of 36°C. The facility is also equipped with a solar simulation system. The boundary layer control system includes a specific system to improve the aerodynamic condition at the dynamometer location during thermal testing. The key instrumentation comprises systems for measuring wind speed, temperature, and humidity, a 6-component force balance built into the turntable, and a flow survey traverse system equipped with a 3-D probe holder mechanism, enabling probe placement anywhere within the test volume. This paper introduces the GAC wind tunnel testing capabilities and design features, presenting results from the aero-acoustic commissioning program. The aerodynamic and acoustic performance results are compared with those of other automotive facilities worldwide.