3D CFD simulations of wind flow and wind-driven rain shelter in sports stadia: Influence of stadium geometry

Sports stadia are increasingly used to host a wide variety of activities that attract large attendances, ranging from sports matches to concerts, festivities and conferences. One of the crucial aspects of spectator comfort in open stadia is protection from wind and rain. However, in many stadia this part of spectator comfort is insufficiently taken care of. The main reason is that stadia and stadium roofs are often designed with only vertical rainfall in mind, neglecting the influence of wind that can sweep the rain onto the stands. This wind-driven rain (WDR) can reach a large area of the stand underneath the roof, resulting in discomfort for the spectators in this area. For stadium design, it is important to understand the interaction between wind and rain in different types of stadium geometry and its effect on wetting of the stands. This paper presents 3D Computational Fluid Dynamics (CFD) simulations of wind flow and WDR for twelve different generic stadium configurations that are representative for a wide range of existing stadia. The wind-flow patterns are determined by steady-state Reynolds-averaged Navier-Stokes (RANS) simulations. The WDR trajectories are calculated using Lagrangian particle tracking, yielding the wetting pattern on the stands. This study demonstrates the influence of both overall stadium geometry and roof slope on the area of the stand that is wetted by WDR. It shows the importance of taking into account WDR in the stadium design process, and it provides some design guidelines to avoid this type of spectator discomfort.