Paper Title
Effect Of Tube Spacing On The Vortex Shedding And Hydrodynamic Forces For Laminar Flow Past A Pair Of Cylinders In Tandem Arrangement: A Numerical Investigation

Abstract
The 2D, viscous and incompressible flow around a single cylinder and then around two circular cylinders in tandem arrangement was numerically simulated using commercial software ANSYS FLUENT 13.0.0. Initially, the computational simulation for a single cylinder was performed in unsteady laminar regime (Reynolds Number, Re= 50, 80, 100, 150, 200, 300). The results obtained were used for validation of working methodology and computational domain. Further, adopting the same methodology, a rigorous study was made for flow over two cylinders and the simulations were performed for different longitudinal gap ratios for tandem arrangement (1.5 < L /D < 5.5) in unsteady laminar (Re =100, 200) regime, where T is the distance between the centers of two cylinders in tandem arrangement and D is the diameter of cylinders. The Reynolds number is based on the diameter of cylinders, D. The pressure field and vorticity distributions along with the associated streamlines and the time histories of hydrodynamic forces were also calculated and analyzed for different gap ratios. Different flow patterns were observed as the gap ratio and Reynolds number varied. Accordingly, variation of hydrodynamic forces at lower and higher gap ratio was studied. This revealed the effect of the Reynolds number and tube spacing on the behavior of flow and vortex shedding characteristics.