Investigation of the Large Eddy Simulation model in wind flow problems over cable-stayed bridges cross sections using the Open FOAM tool

Abstract

With the advent of computational technology, the Computational Fluid Dynamics simulation of numerous and complex problems in several engineering areas has been possible, such as wind-structure interaction. In this interaction, the aerodynamic efforts attributed to the bridge deck movement under the action of wind produce self-excited vibrations at high wind speeds. In this way, a phenomenon is known as flutter, a dynamic instability that involves divergent oscillations can lead a flexible structure to collapse. However, some deficiencies show up when intending to work with these problems using the CFD approach. In general, flows are turbulent with a high Reynolds number, and the use of a turbulence model is needed. Therefore, the use of an appropriate turbulence model is essential, mainly when intending to analyze the dynamics response of the deck where it is fundamental to ascertain the vortex shedding's effect. In this respect, in order to analyze the behavior of wind action on a cable-stayed bridge cross-section, the main purpose of this work is to investigate the LES model of turbulence using an open-source CFD promising tool, Open FOAM. To this end, the Strouhal number and the aerodynamic coefficients will be obtained: drag, lift and moment coefficient of the sectional model subjected to a wind flow with a certain velocity and different angles of attack.(AU)