Research on flow induced vibration tandem towers under passive control

The flow-induced vibration (FIV) of the tower is one of the important reasons for tower failure. It is very important to take effective manual measures to control FIV for the safety and operation of the tower. Helical strakes can effectively interfere with the Karman vortex street and suppress vortex-induced vibration of isolated structures. Due to the vortex structure interaction, the mechanism of FIV control of helical strakes on tandem cylinders remains to be studied. The idealized model of a multi cylinder system with elastic support has been recognized in many fields, such as aviation engineering, nuclear engineering, ocean engineering, and wind engineering. Therefore, in this paper, the tandem cylinders wind tunnel experiment is designed, and a helical strakes installed on the wall of the cylinder model of the tower is designed. The structural dimensions and shapes are mainly involute, square, and D-shape. The vibration respond of the cylinder model at different distances are explored, and the effects of different sections, screw pitches, and helical strakes fin heights on the crosswind vibration response of the cylinder model are investigated. Compared with a series of smooth cylinders, the vibration amplitude of the cylinder with a D-shape helical strakes is reduced by 89%. Furthermore, based on a D-shaped section, the influence of two parameters of helical strakes h (fin height) and P (pitch) on the amplitude response of tandem cylinders is explored, and the parameters of optimal D-shaped helical strakes under different spatial arrangements are given. The research results can be used for the vibration reduction research of tandem towers.