Effect of the free-stream turbulence on the bi-modal wake dynamics of square-back bluff body

• DOI: 10.1063/5.0134912
• Publication Date: 2023-01-08T06:42:35Z
• Authors: Guang Chen; Xiao-Bai Li; Kan He; Zhi Cheng; Dan Zhou; Xi-Feng Liang
• Keywords: Vortex shedding; Wake turbulence; Kármán vortex street

The effect of a free-stream turbulence intensity level on the wake dynamics square-back Ahmed body is modeled using improved delayed detached eddy simulation at Re=9.6×104. center pressure, pressure gradient base surface, and barycenter momentum deficit plane are analyzed to characterize bi-modality dynamics. Given that different flow have dominant frequencies, spectral proper orthogonal decomposition utilized separate bi-stability, pumping motion whole recirculation region, Von Kármán vortex shedding shear layer instability. results show entrainment oncoming into enhanced, vorticity thickness thickened length region decreased with increasing turbulence, resulting in lower suction higher stress. frequency increased increase intensity, while irrespective background turbulence. Though correlation between switching rate cannot be put forward due relatively short numerical time compared wind tunnel experiment, it still known has positive bi-stability switching.