STUDY ON THE WAKE EXCITATION OF A CIRCULAR CYLINDER IN THE WAKES OF RECTANGULAR CYLINDERS

Abstract

Wake excitation is an important problem for tandem circular cylinders. It is well known that this phenomenon is caused by the interaction between the downstream cylinder and the wake flow of the upstream cylinder. However, this phenomenon is affected by the Reynolds number because the flow properties around a circular cylinder are sensitive for this parameter. To simplify this phenomenon and investigate the only interaction between the downstream cylinder and the wake flow the Re-number effect should be reduced. In this study, some kinds of rectangular cylinders were used instead of the upstream circular cylinder to reduce the Re-number effects. It was aimed to understand the influence of the separation flow from the upstream rectangular cylinder on the aerodynamic response of the downstream circular cylinder, and to examine the excitation mechanism of the downstream circular cylinder. Two kinds of wind tunnel experiments were carried out as follows; Model response measurement with two degrees of freedom system and the surface pressure measurement of the downstream circular cylinder.