Abstract
Lift forces and flow configurations of two circular cylinders in staggered arrangements at a subcritical Reynolds number of 5.5×(10)^4 were investigated experimentally. For very small spacings, lift forces acting on the cylinders change drastically with change in spacing ratio and are mainly governed by the behavior of the flow in the gap between the cylinders. The action of lift force acting on the upstream cylinder is attractive (negative) for smaller stagger angles and is repulsive (positive) for higher stagger angles. Bistable nature of flow at a series of spacing ratio is detected for two staggered circular cylinders.
