Intermittency patterns in the chaotic transition of the planar flow past a circular cylinder

The present paper investigates the planar flow past a circular cylinder for Reynolds numbers between 1000 and 10 000. The flow is studied as a dynamical system, so the present investigation is motivated by the presence of complex patterns, as the Reynolds number increases, in the force-time signals when the system goes from the periodic to the chaotic regime. The 2D numerical simulations were performed with a Lagrangian particle method called diffused vortex hydrodynamics (DVH). This computational approach allows high spatial resolutions with an accurate description of different vortical scales shed in the flow field. Flow analysis was executed with the typical tools used in the study of dynamical systems (i.e., Fourier spectra, Poincaré sections, and phase space maps) and is supported by discussion of the near and far wake topologies. During the transition of the system from a regular to a chaotic regime, the lift time signal shows intermittent irregular patterns.