Comparison of wind-driven rain load on building facades in the urban environment and open field: A case study on two buildings in Zurich, Switzerland

Wind-driven rain (WDR) is one of the largest moisture sources affecting hygrothermal performance and durability building envelopes. Accurate estimation WDR loads on facades as boundary condition important for analysis In this work, computational fluid dynamics (CFD) simulations semi-empirical models are used to compare load in urban environment open field. The research focuses two historical buildings city center Zurich, Switzerland. There a very large difference terms local wind-flow fields around Raindrop trajectories field more horizontal due higher wind speeds building. environment, speed lower yielding droplets following that parallel facades. overhang effective at protection compared larger sheltering effect, since distribution facade much smaller than When case study, there uncertainty prediction predicted can be many times by CFD.