Numerical Simulation of Wind-induced Transverse Vibration of a 2D Square Cylinder

Abstract

ABSTRACT Wind-induced transverse vibration of a two-dimensional square cylinder was numerically simulated, based on commercial code Fluent. The Reynolds number, defined by inflow velocity and the depth of the cylinder, was set to be 22000. The fluid-structure coupled system was solved by employing partitioned coupling scheme. The fluid field was simulated using SST k- turbulence model, and the structural motion was calculated by Newmark method. The solution procedure was programmed by user define function (UDF). Flow around the cylinder at stationary state was firstly simulated to obtain initial flow field condition for the coupled system. Wind-induced transverse vibration of the cylinder was then simulated at different reduced wind velocities. Wind-induced galloping, the beat-phenomena and vortex-excited resonance of the cylinder in the transverse direction, were all captured, with the increase of the reduced wind velocities. The simulated data were also compared with those of previous studies. The comparison results showed that the present method is applicable in solving wind-induced vibration problems. Finally, parametric analysis of Scruton number’s effect on the across-wind vibrations of the cylinder was investigated. The results indicated that wind-induced vibration of the cylinder was remarkably affected by the Scruton number. The transverse vibrations were obviously divided into galloping and vortex-induced vibration at large Scruton number, while the switch between the two vibration types was not so remarkable when the Scruton number was low.