Pseudo three-dimensional simulation of aeroelastic response to turbulent wind using Vortex Particle Methods

Abstract

This paper presents a numerical method for analysing the aero-elastic response of bluff line-like structures subjected to turbulent wind. Simulating the buffeting response of line-like structures such as bridges and towers requires accurate modelling of atmospheric turbulence, the cross-sectional aerodynamic behaviour and the structural dynamics. Here the fluid–structure interaction problem is solved considering a three-dimensional structural model coupled with a series of two-dimensional Computational Fluid Dynamics simulation slices, utilising the Vortex Particle Method. The coupled set of simulation slices accounts for the three-dimensional dynamic characteristics of the structure and the turbulent inflow conditions. This pseudo three-dimensional approach is presented as an accurate, yet computationally cheaper alternative to fully three-dimensional simulations of the fluid–structure interaction problem. For the inflow conditions in each simulation slice, the characteristics of the turbulent wind are modelled through pseudo-random velocity time-histories that satisfy the mean velocity profile, spectral properties and spatial coherence of the three-dimensional turbulent wind assumed. The wind field is modelled through vorticity injected at the upstream boundary of the simulation domain. The different components of the method are presented and validated. Finally, the method is applied to the study of a cable-stayed bridge, and the results are validated against wind tunnel measurements.