Experimental Study of the Dependence of Strouhal Number and Mean Drag on the Arrangement of a Circular Cylinder Behind an Airfoil

The interaction between wakes of bluff body and airfoil has profound influences on system performance in many industrial applications, e.g., turbo-machinery and cooling fan. The present work investigates the effect of configuration including airfoil’s angle of attack and transverse spacing of the models on frequency behavior of the cylinder’s near-wake. The experiments were carried out under subcritical flow regime, using hot-wire anemometry (HWA). The relationship between the Strouhal numbers, mean drag coefficient, and arrangements provide an insight into the global physical processes of wake interaction and vortex shedding. Present results show three basic types of flow pattern of wake interference, namely (1) Extended-Body Pattern, (2) Critical Pattern, and (3) Co-Shedding Pattern.