CFD analysis and experimental comparison of novel roof tile shapes

Using an experimental rig, the air pressure difference and the volumetric flow rate between tiles have been measured for an existing Portoghese tile design over a range of pressures. Then, in order to understand the air flows under different conditions, a three-dimensional computational fluid dynamics (CFD) model has been implemented to recreate the full geometry of the rig. The model was calibrated against the aforementioned experimental results, and run with boundary conditions simulating different wind directions. Even in the low velocities typical of average local wind patterns, the fluid dynamic problem remains complex because of the geometry of the gaps between the tiles. However, it has been possible to assess the coefficient of local head loss and then apply it in an analytical relationship between pressure drop and flow rate, taking into account the open area. The results have shown how the wind direction affects the air permeability and, therefore, important insights have been gathered for the design of novel tiles.