Shanghai Automotive Wind Tunnel Center, Tongji University, Shanghai, 201804, China
Department of Civil Engineering, School of Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems, Shanghai, 201804, China
In the present research, a possible generation mechanism of low-frequency buffeting phenomenon based on a 1:15 open jet automotive wind tunnel was investigated. Evolution of vortex structures and pressure field in the plenum chamber have been visualized and analyzed by Large-eddy simulation (LES). It is shown that the low frequency pressure fluctuation is caused by the large-scale structures and their interaction. Multiple proper orthogonal decomposition was adopted to analyze the flow field in the plenum chamber. The characteristic frequencies of the vortex-rings after pairing is the same as the dominant resonance of buffeting at this wind velocity.