Wake Interactions Around a Pair of Porous Cylinders in a Side-By-Side Arrangement in Channel Flow

In this study, we have investigated the flow around two side-by-side porous cylinders in a confined channel. The study reports various flow patterns as well as an absolute suppression of the vortex-shedding process at high permeability levels. An unsteady flow at Reynolds number Re = 150 at two different parameters, Darcy number (Da) and gap ratios (s/d) for the ranges of Da = 10–6−10–2 and s/d = 1.5–6, is found to exhibit asymmetric flip-flop and synchronized anti-phase wake patterns. A jet-like flow in the vicinity of cylinders, mainly on the gap side, controls the wake patterns. A jump in the flow characteristics in the intermediate range of Darcy number is also explained by means of backflow phenomena. The velocity profiles on the freestream sides, the gap side, and the surface pressure distribution curve are discussed to give insight into the formation and suppression of wakes. The effects of gap ratios and Darcy number on the drag coefficient are also examined.