Aerodynamic behaviour of a square cylinder placed in a turbulent plane mixing layer

Abstract

This paper describes experimental results for the aerodynamic behaviour of a square cylinder placed near and in a turbulent plane mixing layer. The time-mean fluid forces have close similarities irrespective of the change of the mixing layer thickness. The flow patterns are classified into two types at the non-dimensional boundary position η B = − 0.05, namely perfectly separated flow and reattachment flow. The fluctuating fluid force has a conspicuous high rise when the cylinder is installed near a mixing layer thinner than the width of the cylinder, which is induced by the oscillation of the mixing layer upstream of the cylinder. However, such a high rise of the fluctuating forces disappears and there is a fairly good similarity with respect to the non-dimensional position η when the mixing layer is more than 1.3 times thicker than the width of the cylinder.