Wind-structure interaction simulations of ovalling vibrations in silo groups

During a storm in October 2002, wind-induced ovalling vibrations were observed on several empty silos of a closely spaced group of silos in the port of Antwerp (Belgium). In this paper, three-dimensional numerical simulations are used to investigate this complex case of wind-structure interaction. The computed amplitude of the ovalling vibrations of the silos is similar to that in the observations, indicating that the adopted modelling approach can be suitable for the analysis of new silo groups.Both one-way and two-way simulations are presented, for a single silo and for the silo group. In the one-way simulations, the wind pressure is applied on the structure, disregarding the structural displacements in the wind flow simulation. By contrast, the two-way simulations also take into account the effect of the structural motion on the wind flow. For a single silo, the one-way and two-way simulations yield similar results. Conversely, for a silo in the group, the ovalling vibrations are significantly larger in the two-way simulations than in the one-way simulations. Consequently, aeroelastic effects and/or interactions between the wake-induced excitation and the vibration are present in the silo group for the investigated case.Furthermore, it is shown that the aerodynamic loading and vibration amplitudes are considerably larger for silos in the group than for a single isolated silo.