A wind tunnel and numerical study on the surface friction distribution on a flat roof with solar panels

This work aims to contribute for a better understanding of how solar panels, installed on a flat roof, affect the potential of aeolian erosion of loose particles deposited on it, influencing processes such as snow drifting. Two methodologies are employed, namely wind tunnel experiments and RANS simulation. Several configurations are studied, varying the distance between successive panels placed in tandem, and gap between the panels and the roof, for two wind orientations. The accuracy of the simulations is examined by comparing predicted results against wind tunnel experiments. It is confirmed that computational simulations, by means of k–ω SST turbulence model, yield the tendency of the static pressure, and also of wall shear stress, distributions along the roof provided that mesh satisfies y+ < 5. It is found that wall friction is considerably affected by the presence of panels and, consequently, the wind erosion process and, therefore, snow drifting on a roof. The computational wall shear stress results are confronted against experimental data, and, taking into account the uncertainty associated to the probes employed, it is found that, despite of high flow complexity, numerical simulations provide reliable information for this research field.