Aerodynamic forces on a cylindrical structure in a wake of another cylindrical structure

Abstract

Measurements of mean aerodynamic force components on a smooth circular cylinder in the near wake of an identical parallel cylinder are presented for different configurations of longitudinal and lateral spacings and over a range of subcritical Reynolds numbers 13 000 to 72 000. The observed symmetrical variations of drag and antisymmetrical variations of lift are empirically correlated on the basis of the geometrical parameters and the flow Reynolds number. Additional information from surface pressure distributions gives more detail and permits deductions to be made on the effects of the main parameters involved in the observed phenomena. Almost all aerodynamic parameters of the cylinder in the wake are strongly altered compared to the respective ones of a single cylinder in uniform flow. The data presented are intended for direct use by practising engineers. They also contribute to the further understanding of the effects of turbulent shear flows on bluff cylinders and the formation of their wakes. While dominant effects could be traced on the basis of measured data, the complexities of the flow studied did not permit separation of all factors contributing to the observed behaviour.