NUMERICAL SIMULATION OF THE OSCILLATORY FLOW AROUND TWO CYLINDERS IN TANDEM

A numerical study on oscillatory flow past two cylinders in tandem is carried out. The Reynolds-averaged Navier-Stokes equations are solved using a finite element method (FEM) with a k-omega turbulence closure. The numerical model is validated against oscillatory flows past a single circular cylinder where the experimental data are available in literature. Then the numerical model is employed to simulate the flow around cylinders in a tandem arrangement. It is found that the distance between the cylinders affects the flow characteristics. Two parallel transverse vortex streets are observed for large distances and two oblique vortex streets for moderate distances. For small distances, only one vortex street can be found. The two cylinders behave like a single bluff body when the distance between the two cylinders is small. The effect of the distance on the force coefficients are investigated in this paper.