Flow around a Circular Cylinder with Radial Disturbances at a Low Reynolds Number

Based on the idea of geometric disturbance in suppressing vortex induced vibration (VIV), numerical simulations are carried out for a flow past a fixed circular cylinder with different wavy disturbances. Two kinds of disturbances, harmony and cone, are considered. Different wavelengths and wave heights are investigated at a Reynolds number of 100. The introduction of disturbance would increase the drag but reduce the lift for most cases. The local minimum of fluid forces exists, presently, at the non-dimensional wavelength of 6. The typical Karman vortex is gradually disturbed with the increasing strength of disturbance. Different flow patterns are identified and discussed, such as Ω-type vortex and the complete suppression of vortex shedding. Characteristics of effect of disturbance on the generation and distribution of surface vorticity are presented in detail.