Numerical simultation of medium rise buildings (subjected to wind loads) using Computational Fluid Dynamics (CFD)

Abstract

High-rise building industry has become more popular with the urbanization all over the world. Tall & medium rise buildings are more sensitive to the wind force than low-rise buildings. Wind action is more significant on the building when the building is getting taller. Therefore, wind induced action should be accurately predicted by considering the building height. Traditional techniques, like code-based wind predictions, are unreliable on wind action when the height of the building increases. However, wind tunnel testing is widely used to predict the wind induced effect using a prototype with the geometric and dynamic similarity for all types of buildings and structures. But wind tunnel testing requires large, expensive equipment and time. Numerical methods also can be used to simulate the wind flow behavior around the building. Computational Fluid Dynamic (CFD) method is a reliable option for wind analysis of tall buildings. Direct Numerical Simulation (DNS) is not possible because of insufficient computational power. Using turbulence models, solutions utilizing the Reynolds Averaged Navier-Stokes (RANS) equation can serve as a substitute for wind analysis. Various types of turbulent models can be developed in Midas NFX software for simulating the wind flow. Nine rectangular-shaped buildings were subjected to rigid body modeling analysis using Midas NFX software inside a well-defined computational area. Obtained results were compared with the code base prediction results & wind tunnel testing results for all buildings. 2-equation k-ω (SST) turbulent model was used to predict the wind pressure distribution around the building and the normalized base overturning moment with the reasonable accuracy with 1m mesh size