Effects of reattachment and three-dimensionality on the aerodynamics of a circular cylinder in the critical Reynolds number range

Details of the aerodynamic characteristics of a circular cylinder in the critical Reynolds number range remain unclear. A significant influencing factor is the occurrence of reattachment. A series of pressure measurements on a circular cylinder of finite length in the critical Reynolds number range, Re = 1.0 x 10(5)-4.6 x 10(5), is carried out in a wind tunnel to reveal the three-dimensional effects of reattachment on the aerodynamics, which cannot be observed by the two-dimensional simulation and significantly influence the estimation of the aerodynamics of slender structures. The results show that the flow can reattach along only a certain length of the cylinder instead of the entire length, inducing a strong three-dimensional flow state and corresponding aerodynamic force distribution. The reattachment also induces an unsteady variation in the aerodynamic force; the lift coefficient is mainly dependent on the occurrence of a separation bubble and the motion of the reattachment point.

Automated summary

This study investigates the aerodynamic characteristics of a circular cylinder in the critical Reynolds number range, revealing that reattachment only occurs along a certain length of the cylinder, inducing a strong three-dimensional flow state and corresponding aerodynamic force distribution. The reattachment also causes an unsteady variation in aerodynamic force, with the lift coefficient mainly dependent on the occurrence of a separation bubble and the motion of the reattachment point.