Steady Flow Past Two Square Cylinders in Tandem

摘要

In the present work, two-dimensional, incompressible steady flow around a pair of identical square cylinders in tandem arrangement is studied numerically using stabilized finite-element formulation. Reynolds number (Re), based on free stream speed and cross-flow width of the cylinder, is fixed at 40. The spacing ratio (S/D) is the ratio of distance between the center of cylinders to the cross-flow dimension of the cylinder which is varied from 2 to 10. Three distinct flow patterns are identified for the given range of S/D. With increase in S/D, the wake interaction between both the cylinders weakens and both cylinders form separate closed wakes for S/D ≥ 6. Interestingly, a weak recirculation zone other than the closed wake structure of both the cylinders is found near the forward stagnation point of downstream cylinder in the gap region. This recirculation zone disappears with a marginal change in the spacing ratio. As S/D is increased further, both upstream and downstream cylinders behave as an isolated cylinder.