In this study, the turbulent flow around the circular cylinder was controlled using a tab. The number of Reynolds considered is 3900 when defined based on the free flow rate and the cylinder diameter. Large eddy simulation using the dynamic global subgrid-scale model was performed for turbulent flow analysis. A pair of tabs were attached to the upper and lower parts of the cylinder surface where flow peeling occurs. In order to find the optimal performance of flow control, a parameter study was conducted on the height and width of the tab and the span direction interval between adjacent tabs. The drag and lift perturbations received by the cylinder in the parameters of the tab producing optimal performance were reduced by 14% and 95%, respectively. In the rear stream of the cylinder to which the tab is attached, the two-dimensional flow structure is disturbed to form a three-dimensional flow structure that changes in the span direction. This weakens the Kármán vortex shedding and reduces drag and lift perturbations of the cylinder. In the case of flow control using a tab, it is expected that it could be practical because it does not require additional energy consumption for control and it can be simply implemented by attaching a tab to the cylinder surface without changing the circular cylinder shape.
