Numerical Investigation of Flow Behaviour Across Three Circular Cylinders in a Stagger Arrangement

A circular cylinder has been applied to the world of engineering with various geometries and is frequently placed in the stream of the fluid flow. The interaction between the flow and the cylinders causes drag, and at certain circumstances, causes lift also. The drag occurs due to the presence of pressure and friction on the cylinder surface. Therefore, in the present study, the researcher tried to investigate the flow behavior across three circular cylinders in a stagger arrangement placed in the airflow. The purpose of this study is to obtain drag reduction that occurs on the cylinder arrangement. This research was conducted numerically using Ansys Fluent® 19.1 and conducted in two-dimensional (2D) Unsteady RANS using the turbulence model of standard k-epsilon. In this study, the longitudinal distance (L/D) has four variations, i.e. L/D = 1.5; 2.0; 3.0; and 4.0 with a diameter of the cylinder (D) = 25 mm. The cylinder arrangement is placed in a narrow channel with a square cross-section Wide x High x Long = 300 mm x 300 mm x 600 mm, the flow Reynolds number in this study is set to be 2.4 x 10⁴. The results showed that the distance (L/D) greatly affects the coefficient of drag of the circular cylinder in that arrangement. The smallest coefficient of drag on cylinders 1 and 2 occurs at a distance (L/D = 3.0), while the smallest coefficient of drag on cylinder 3 occurs at a distance (L/D = 2.0).