722 Water Tunnel Tests on In-Line Oscillation of a Circular Cylinder with a Finite Length in a Turbulent Flow

Abstract

In-line oscillation of circular cylinders in a turbulent flow was studied by carrying out the water tunnel experiments with circular cylinders that have finite span lengths, which were supported elastically in two degrees of freedom (in-line and transverse direction). Also, Screens set in the water tunnel generate turbulent flow. As a result, in the case of aspect ratio 15 cylinder, it shows the large response amplitude both in the 1st and in the 2nd excitation region. And the amplitude in the 2nd excitation region is dampened, as the turbulence intensity is larger. Furthermore, the Lissajous figure at 2nd peak changes from a figure of 8 in a smooth flow into a complex elliptical orbit in the high turbulent flow.