Flow characteristics around two parallel adjacent square cylinders of different sizes

摘要

This paper presents the results of the aerodynamic forces and vortex sheddings of two square cylinders in side-by-side arrangement of size ratio 2:1 at subcritical flow regime. Flow measurements were carried out at transverse spacing of 1.12 T/D 5 2.5. The gap side shear layer of the large cylinder reattaches to its inner face for small separation, while the gap side shear layer of the small cylinder reattaches to its inner face for larger separation. The distributions of aerodynamic forces reveal that maximum pressure loading on the small cylinder occurs at a separation of T/D = 1.75. The coefficient of moment CM remains negative for the different transverse spacings studied and a point of inflexion is found at T/D = 1.25. The trajectories of the vortices from the cylinders and the mean and fluctuating velocities of the wakes at x/D = 2.0 show that the flow is skewed towards the small cylinder. No bistable flow is found within the transverse spacing studied.