Dust deposition processes and behaviors on ground-mounted solar photovoltaic (PV) arrays were investigated by shear stress transport k-omega turbulence model and the discrete particle model. Inlet velocity and turbulent kinetic energy distributions fitted from experimental data were imposed in the simulation to improve prediction accuracy. After mesh independent test and numerical verification, air flow fields over the solar PV array, dust deposition rates for different rows of PV panels and different dust diameters were investigated. It was found that dust deposition rates on solar PV panel array are declined from the front to the back row. Maximum deposition rate from the first to the fifth row of PV panels is 18.89%, 12.35%, 9.62%, 6.83% or 5.71% respectively. The corresponding dust diameter for the peak deposition rate is 350, 250, 200, 150 or 150 mu m respectively. The main deposition mechanisms were investigated by analyzing dust motion trajectories on PV panel arrays. Furthermore, Maximum PV output reduction induced by dust can reach 79.77%, 18,16%, 5.88%, 2.66% or 1.89% from the first to the last row of PV panels, respectively. Therefore, the most degradation of PV efficiency appears for the first row of PV panels. (C) 2018 Elsevier Ltd. All rights reserved.