DNS of Turbulent Channel Flow With a Flexible Square Cylinder

In the present paper in order to investigate possibility of flow control using elastic body, we conduct a simulation of a finite-length flexible cylinder installed in turbulent channel flow. For the flexible cylinder, the rigorous equation of motion for elastic continuum is solved with a finite volume method; the effect of existence of cylinder in the flow computation is taken into account using the immersed boundary method. From instantaneous and time averaged flow quantities, we demonstrate that the flexible cylinder markedly modulates the wake structure depending on the elasticity of cylinder. Further in order to extract coherent structures, the DMD (dynamic mode decomposition) method are applied. The primary flow structures in the wake of cylinder are demonstrated.