FIV response analysis of cylinder with hollow section placed in tandem at the rear of upstream cylinder by numerical simulation.

The flow-induced vibration of a circular cylinder with a hollow section that is mounted at the rear is investigated in this work via numerical simulation. The Reynolds number was limited in the range of 6918–1511 by using reduced velocity that corresponds to Ur = 2–12. Five typical center-to-center distance ratios L/D of 3, 4, 5, 6, and 7 and three hollow section positions of left bias, up bias, and middle of cylinder were selected. The displacement time history curve and short-time Fourier transform diagram show that when L/D = 3 and Ur = 3, the cylinder with the hollow position in the middle initially entered the main frequency vibration for 5.64 s, but when L/D = 4 and Ur = 6, the drag coefficient time history curve of the cylinder biased to the left and up at the hollow position demonstrated a "beating" phenomenon, and multiple frequency peaks appeared on the fast Fourier transform diagram. [ABSTRACT FROM AUTHOR]