Numerical investigations on the along-wing response of a vibrating fence under wind action

The along-wind response of a surface-mounted elastic fence under the action of wind wasrninvestigated numerically. In the computations, two sets of equations, one for the simulation of thernunsteady turbulent flow and the other for the calculation of the dynamic motion of the fence, were solvedrnalternatively. The resulting time-series tip response of the fence as well as the flow fields were analyzedrnto examine the dynamic behaviors of the two. Results show that the flow is unsteady and is dominated byrntwo frequencies: one relates to the shear layer vortices and the other one is subject to vortex shedding.rnThe resulting unsteady wind load causes the fence to vibrate. The tip deflection of the fence is periodicrnand is symmetric to an equilibrium position, corresponding to the average load. Although the along-windrnaerodynamic effect is not significant, the fluctuating quantities of the tip deflection, velocity and accelerationrnare enhanced as the fundamental frequency of the fence is near the vortex or shedding frequency of thernflow due to the occurrence of resonance. In addition, when the fence is relatively soft, higher modernresponse can be excited, leading to significant increases of the variations of the tip velocity and acceleration.