Application of CFD for assessment of galloping stability of rectangular and H-sections

Abstract

Wind induced aerodynamic forces are considered to be important for the design of buildings and structures. Additional aerodynamic forces, which can cause instability,are induced in flexible structures like suspension/cable stayed bridge decks owing to wind-structure interaction effects. Hence, it becomes necessary to assess the stability of cross-sections of such bridge decks against the effects like galloping and flutter. In the present study, towards the application of CFD as a numerical tool in assessing the stability of bridge cross-sections against transverse galloping, smooth flows around three 2-D rectangular sections and a 2-D H-section representing a realistic bridge deck cross-section have been numerically simulated for various angles of wind incidence at Reynolds number of 61000. Two of the popular RANS turbulence models, namely Realizable k-e (RKE) and Shear Stress Transport k-w model (SST) available in commercial CFD code FLUENT have been used. The numerically evaluated aerodynamic drag and lift force coefficients and their variations with angle of wind incidence have been used to assess the stability of the sections against transverse galloping using quasi-steady assumption.Further, the numerically evaluated aerodynamic force coefficients have been compared with the experimental results available in literature for the validation of CFD simulations.