Radial Deformation Frequency Effect on the Three-Dimensional Flow in the Cylinder Wake

In the current paper, the three-dimensional air flow evolution around a circular cylinder is studied. The main aim is to control the flow field upstream and downstream of a circular cylinder by means of radial deformation. Within a particular step, one focuses on the response of the topological structures, which is developing in the cylinder near wake to applied pulsatile motion. Furthermore, a special care is considered to the aerodynamics forces behavior in adjusting the applied controlling strategy. The used controlling frequency range extends from f = 1fn = 17 Hz to f = 6fn = 102.21 Hz, which corresponds to a series of multiharmonic frequency varying from one to six times the natural vortex shedding frequency (VSF) in none forced wake. Throughout this work, the forcing amplitude is fixed at 16% of cylinder diameter and the Reynolds number as Re = 550. Through Fluent computational fluid dynamics (CFD) code and Matlab simulations, the obtained results showed a good accordance with the calculated ones.