A New Definition of Vortex Formation Length
摘要
We introduce a new definition of vortex formation length for uniform steady flow past a circular cylinder using Proper Orthogonal Decomposition (POD) of the pressure field. Previous definitions each identify a single characteristic length for a given value of Reynolds number. We use the leading modes of the pressure POD to define upper and lower bounds on the vortex formation length. Identifying a range for the vortex formation length is consistent with the hysteresis observed in the critical spacing of two tandem cylinders.