Abstract:
This study presents a numerical investigation of the flow characteristics around a single and
double-slotted cylinder using computational fluid dynamics (CFD). The simulations were
conducted using CFD software OpenFOAM on a structured grid. The governing equations for
incompressible, laminar flow were solved using the SIMPLE FOAM solver. A mesh-independent
study led to a structured grid with 0.7m cells which was sufficient to capture the flow features
accurately. The results show that the addition of double slits to the cylinder significantly reduces
the drag coefficient as compared to a normal cylinder. The reduction in drag coefficient was
observed to be more significant for wider slits, with a maximum reduction of 22% observed for a
gap between slits and a width-to-diameter ratio of 0.1. The streamlines and pressure contours for
the double-slotted cylinder show a distinct change in the flow pattern due to the presence of the
slits. The flow around the slotted cylinder is observed to be more streamlined with less vortex
shedding as compared to the no-slit cylinder. Additionally, the slits help in reducing the size of the
wake region behind the cylinder, resulting in a reduction of pressure drag. The effect of the
Reynolds number on the flow characteristics was also studied. It was observed that the increase in
Reynolds number resulted in a decrease in drag coefficient for each set of cases, similar to that of
a no-slit and single-slotted cylinder. The results of this study suggest that the presence of double
slits can significantly alter the flow characteristics of a cylinder and improve its aerodynamic
performance, especially in laminar conditions. The findings of this study can have potential
applications in various fields, including aerospace, wind energy, and marine engineering.
