High Reynolds number incompressible crossflow on a rectangular cylinder near a plane wall boundary*

Classical literature on different types of cylinders (rectangular or circular) in crossflow have well established the relationship between the drag coefficient versus the Reynolds number; where in the drag coefficient is generally independent of viscous effects beyond a critical Reynolds number.

This study takes the classical cylinder problem and introduces a single plane wall boundary near the rectangular cylinder resulting in a gap between the cylinder and the plane wall. This model is investigated under high Reynolds number incompressible flow. Because of the proximity to a plane wall boundary, the classical symmetric von Kármán sheet becomes asymmetric. Additionally, the characteristics of the flow are no longer independent of the Reynolds number. The geometric setup can be described as semi-confined, with the cylinder confined by a free slip “atmospheric” boundary on one end, and a no slip plane wall boundary on the other end.

This work has applications in crosswind with road vehicles and trains, aerodynamics of an airplane on a runway, engineered debris structures, mechanical fluid systems, and marine and coastal systems to name a few examples.