Low-order modelling of the wake dynamics of an Ahmed body

We investigate the large-scale signature of random switches between two mirrored turbulent wake states flat-backed bodies. A direct numerical simulation (DNS) flow around an Ahmed body at a Reynolds number ( $Re$ ) 10 000 is considered. Using proper orthogonal decomposition (POD), we identify most energetic modes velocity field and build low-dimensional model based on first six fluctuating capturing characteristics dynamics during switches. In absence noise, produces with characteristic time scales in agreement experiments. This chaotic suggests that are triggered by increase vortex shedding activity. However, addition noise results better temporal spectra coefficients simulation.