FLOW STUDY IN CONFINED-CHANNEL AROUND TWO PERMEABLE SIDE BY-SIDE ARRANGED CYLINDERS

Abstract

Flow around and through permeable circular cylinder arranged in side-by-side configuration is investigated in this work. The focus of this study is to get better understanding of fluid dynamics (recirculating wake length) around a porous bluff body by studying streamline contours, vorticity contours, pressure coefficient long the surface of porous cylinder and velocity profile. The range of Reynolds number (Re) and Darcy number (Da) used in current research is between 1 to 40 and 10-6 to 10-2 respectively for the gap ratio (s/d) of 1.5, 2, 3.5 and 6. The porosity of cylinders corresponding to above Darcy number varies from 0.629 to 0.993. For this range of parameters used the flow filed remain in steady state (laminar regime) and symmetric along the centerline of channel, due to purely forced convection in this confined domain. The effects of all (Reynold number, s/d and porosity) is examined and it has been found that there is a slight jump in CD valve on increasing permeability form Da=10-4 to Da=10 3for Re>20. As the porosity increases the effect of gap ratio diminishes. On observing flow pattern of an individual cylinder there is an asymmetric recirculating regions occurred behind the cylinder due to influence of one cylinder over other.