Airborne dust-induced performance degradation in NREL phase VI wind turbine: a numerical study.

The meteorological conditions markedly affect the energy efficiencies and cost/power rate of the wind turbines. The dusty environment is common in arid windy areas and airborne particles generally degrade wind turbine performance. The National Renewable Energy Laboratory (NREL) Phase VI wind turbine has been designed to be insusceptible to surface roughness, a consequence of facing dusty winds. This study numerically investigates the wake flow topology and analyses the performance of this turbine for either clean or dusty air. First, the numerical approach is validated against the available experimental data for clean air. Following this, the model is developed into a Lagrangian-Eulerian multiphase approach to comprehensively analyze the effects of the dusty air. The dependence of aerodynamic performance on the wind speed (U_∞ = 5–25 m/s), particle diameter (d_p = 0.025–0.9 mm), and angle of attack (AoA = 0°–44°) is investigated. The turbine performance deteriorates acutely for d_p ≥ 0.1 mm and post-stall state. As such, the generated power is reduced by 4.3% and 13.3% on average for the air with the d_p = 0.05 and 0.9 mm, respectively. The particles change the flow field profoundly, declining the pressure difference between the suction/pressure sides of the blade-airfoil, advancing the boundary layer separation, and strengthening the recirculation zones. The above changes account for a lower lift coefficient and a higher drag coefficient. [ABSTRACT FROM AUTHOR]