Aerodynamic Characteristics of Circular Cylinders Vertically Mounted on a Plane Wall -Relation between the drag coefficient and the characteristics of turbulent boundary layers

摘要

An experimental investigation is carried out on the flow around a circular cylinder vertically mounted on a smooth plane wall along which a turbulent boundary layer is fully developed. The pressure drag of the cylinder is correlated with the height h, the diameter d of the cylinder and the characteristics of the boundary layer. The pressure drag coef ficient C_D is found to be expressed in the form C_D=a･(h/δ)^b, where δ is the thickness of the boundary layer and the values of a and b depend on h/δ. For h/δ ＜__?1.1, a and b are linear functions of d/δ only while they are constant in the range h/δ＞__?1.1.