Characteristics of flow fields and particle transport in photovoltaic array over complex terrain

This study develops a complex terrain model using real elevation data to systematically investigate the interactions between a photovoltaic (PV) array and particle transport. The results indicate that the complex terrain creates a highly non-uniform flow field, vertically dividing the average wind speed into four zones: speed reduction, high-speed, low-speed above the panels, and flow recovery, whose boundaries rise with increasing terrain height. Fewer disturbed PV panels result in a faster flow recovery to the logarithmic profile. The complex terrain also forces vortices to form closer to panels, breaks their symmetry, increases their shedding frequency, and enhances the spatial dispersion of turbulent kinetic energy. Both the high-turbulence zone behind panels and convex terrain elevate particle saltation height. Furthermore, over complex terrain, the particle transport flux first increases and then decreases with height, with its peak value decaying downstream. In concave regions, near-wall particle flux remains low, and its peak shifts toward the windward edge. Conversely, convex terrain raises both the flux and its peaks. Particles rebounding from panel surfaces generate a secondary flux peak, with a more obvious suppressive effect by panels over the convex terrain, where the second peak is higher. This investigation provides theoretical and technical support for predicting particle deposition around PV array and optimizing their layout in complex terrain.