Finite element formulation for the analysis of turbulent wind flow passing bluff structures using the RNG k−ε model

This paper presents a stable finite element formulation to predict behaviors of high-speed wind passing bluff structures using the Reynolds averaged Navier–Stokes equation and the k–ε model. To incorporate the k–ε model with the finite element framework, a stable and accurate solution strategy is proposed. The streamline-upwind/Petrov–Galerkin scheme is adopted to stabilize the Reynolds averaged Navier–Stokes equation as well as the k–ε equations. The re-normalization group k–ε model is employed to reduce the turbulence over-production around the stagnation points on the upwind side of structures. Detailed discussions on the flow behaviors around the bluff structures are made through examples of wind flows passing a square cylinder and actual bridge sections to validate the proposed formulation. It is shown that the periodicity and magnitude of unsteady forces acting on the square cylinder are well predicted. Aerodynamic forces acting on bridge girder sections with complex geometry are presented for high-speed wind with the Reynolds number over 107, and compared with experimental results.