A Parametric Study of Wind Pressure Distribution on Facades Using Computational Fluid Dynamics

Featured Application Efficient design of facade elements for wind loading. This paper uses Computational Fluid Dynamics (CFD) to determine wind pressures on facades for the purpose of efficient design of these elements. An outstand fin arrangement was modeled where local brackets are used to protrude the fins from the building. A parametric study, for both changes in the length of the bracket and the fin, was derived from CFD simulations with 1-in-50-year storm conditions adopted throughout. Further simulations are performed for revised wind directions that ensure all fins are equally exposed to oncoming winds. In total, 15 models are created to act as a representative sample of the total number of possible configurations. Peak values for pressure are used to calculate forces and moments on the fins. These wind loading results were then used to interpolate the values for the remaining facade geometries. From interpreting the trends that are apparent in the relationship of fin size and bracket length to efficient loading, a set of design criteria is established. The optimal facade design is defined, based on placing equal importance onto minimizing the force along the fin's length and the moment acting at the fin-bracket connection. The performance of some facade elements is shown to worsen the effects of the wind, relative to other designs, with the potential for very negative consequences. Wind direction is shown to have a significant effect on loading, with the magnitude of wind pressures reduced considerably for the worst affected fin, if the sheltering effect is absent between the fins.