DRAG IN STREAMWISE ROWS OF CIRCULAR CYLINDERS ARRANGED IN A STRAIGHT CHANNEL FLOW

Abstract

Drag in rows of circular cylinders arranged parallel to the main flow in a straight duct is examined by high-resolution numerical simulations based on an immersed boundary method. It is found that shifting the row of cylinders toward the side wall achieves a considerable drag reduction. When a row is allocated along the centerline of the flume, the flow resistance solely depends on the number of cylinders, irrespective of the configuration details. It is also revealed that the flow resistance is maximized at which the surface-to-surface distance between neighboring cylinders is around the cylinder diameter and is closely associated with the lateral mixing of the flow.