Stagnation and Reattachment Lines on a Cylinder of Square Cross-section in Smooth and Turbulent Flows

Abstract

Flow visualization experiments have been performed to ascertain the positions of stagnation and reattachment lines on a cylinder of square cross-section at various angles of incidence with and without turbulence in the ambient flow. Vickery1 found that the introduction of turbulence into the ambient flow caused a significant increase in base pressure coefficient at low angles of incidence. He tentatively explained this effect by supposing that the turbulence caused reattachment. McLaren et al.2 explained their data by the same supposition and it is also accepted in the discussion of Hunt3 on flow around buildings. Kavur4 found, however, that no reattachment occurred at zero angle of incidence even for extremely high levels of turbulence. This disagreement is discussed by Bearman5. My investigation was intended, in part, to throw light on this problem.