Two side-by-side cantilevered cylinders in a cross flow

Three dimensional flow over two side-by-side cantilevered cylinders is numerically studied for understanding the complex wake interference behind the cylinder pair. The two cylinders stand on the ground. The lattice Boltzmann method with multiple relaxation time is used for the solution of three dimensional unsteady flow. The simulations are carried out with Reynolds number Re = 200, aspect ratio L/D = 10 and four transverse pitch ratios : T/D = 1.2, 1.5, 2.0 and 3.0, where Re is defined by incoming velocity U, cylinder diameter D and kinetic viscosity v, L is cylinder span length and T is center to center spacing between the cylinder pair. Numerical results show that the wake patterns depend on not only T/D, but also the end flow conditions. Both the wake street and statistics of fluid force vary along the cylinder span considerably, indicating strong three dimensionality of the wake flows and their interaction.