Evaluation of numerical techniques for modeling flutter phenomenon into two geometries: the 1:4.9 rectangle and the Great Belt East Bridge in scale 1:7

The flutter phenomenon must be carefully evaluated, as it can lead structures to collapse. This study presents a methodology based on computational fluid dynamics to obtain the flutter derivatives and the critical flutter velocity, through forced vibrations in bodies immersed in a fluid medium. Two approaches were analyzed. In the first (8COEF), torsion and flexural movements were imposed. In the second, simulations were carried out in torsion mode, and through linear equations (LE), the complete set of eight coefficients was obtained. While the first can be seen as the most robust, as all coefficients are obtained from computer simulations, the second is less computationally expensive. The study was applied to a 1:4.9 rectangle and to the cross-section of the Great Belt East Bridge (GBEB). The simulations were submitted to turbulent flow with Reynolds number equal to 10 ^5 , using k– ω SST and k– ω SSTLM turbulence models. For the static case, simulations were performed to obtain the average values of the aerodynamic coefficients. OpenFOAM® was used to solve the Navier–Stokes equations for an incompressible fluid. The critical flutter velocity for the GBEB was estimated using the 8COEF and the LE approaches. It was noticed that the results estimated with the LE were effective and with a good approximation with those of the 8COEF but at a lower computational cost. All results were validated with numerical and experimental studies available in the literature. Finally, this research stands out in presenting an assertive and pragmatic CFD methodology to obtain critical flutter velocity on structures.