Vortex loop development behind a polygonal disk

Understanding the vortex dynamics in the wake of an impulsively started disk have several applications in modelling biological drag-based propulsors, such as fins on fish. Better understanding of these vortex dynamics can help us better develop force and turbulence models. While most existing research focuses on the wakes of circular disks, this work investigates the development of the vortex loop behind impulsively started polygonal plates, specifically triangles, squares, pentagons, and hexagons. The plates are set in motion with Reynolds number Re = 20,000. Vortex loop size, vortex trailing distance and azimuthal instabilities are found to be strongly influenced by plate geometry which, in turn, affect the transient forces on the plate.