Identification of Aerodynamic Derivatives of a Box-Girder Bridge Deck with Twin Active Flaps Using CFD Simulations

Abstract

A practical identification method based on single-degree-of-freedom (SDOF) forced vibration was proposed and its application to obtain 16 aerodynamic derivatives of a box-girder bridge deck with twin active flaps (termed as the deck–flap system) was discussed in detail. Two-dimensional numerical simulations based on the unsteady Reynolds-averaged Navier–Stokes (URANS) approach with the shear stress transfer (SST) k–ω turbulence model were conducted to investigate transient motion-induced aerodynamic forces, which were further calculated by the present method to acquire aerodynamic derivatives of the deck–flap system. Moreover, cases of a separate bridge deck and a plate–flap system were taken as examples, and the corresponding results were in good agreement with experimental data and theoretical values, respectively, demonstrating the reliability and accuracy of the proposed identification method. Based on the effects of vibration amplitude and phase angle, the application scope of the present method was discussed to verify its usage in physical wind tunnel experiments.