Active Flow Control of Flow Over a Stationary Cylinder Using a Flapping Rod at Low Reynolds Number

A numerical investigation of the active flow control mechanism of flow over a stationary circular cylinder using a flapping rod was conducted at low Reynolds number. The Galerkin-least-square (GLS) stabilized Finite Element formulation in Arbitrary Lagrangian-Eulerian (ALE) description is employed to investigate the fluid dynamics and structural motions in the simulations. A rotating dynamic mesh model is utilized to precisely trace the flapping dynamics of the control rod in the wake downstream. A control rod of very small diameter (d = 0.1) is used as an active flow control mechanism and flaps behind a cylinder (D = 1.0) in an orbital manner at a range of frequencies, amplitudes, and distance. The primary objective of this study is to investigate the effectiveness of this flapping rod to enhance the structural stability of the cylinder subject to hydrodynamic forces. The results show that this active flow control mechanism, flapping control rod, can effectively change the wake modes downstream and enhance the structural stability by minimizing the fluctuation of lift force.