CFD wind-driven rain simulations and their use for HAM modelling

Wind-driven rain is one of the most important boundary conditions for numerical Heat-Air-Moisture (HAM) transfer models. Due to the complexity of WDR however, the current HAM models generally incorporate it in a very simplified way. Recent research has shown that CFD can provide accurate estimates of WDR on building facades. Therefore, in this paper, a combined CFD-HAM approach is presented. It is applied for a simplified wall model. It is shown that the accuracy of the HAM-simulation results is to a large extent determined by the time resolution of the meteorological input data and by the data-averaging technique used for these data. Some guidelines for accurate HAM analyses with WDR are provided.