CFD simulation of the effect of rain on the performance of horizontal wind turbines

Abstract

Wind turbine power output is influenced by environmental conditions, including rain. Therefore, a better understanding of the effect of rain on the performance of wind turbines is necessary. Our coupled Lagrangian-Eulerian multiphase computational fluid dynamics model was modified to more accurately simulate the momentum transfer during water film formation on the airfoils of a horizontal-axis turbine and the performance loss caused by the rainwater film on the National Renewable Energy Laboratory (NREL) turbine performance. To obtain three-dimensional numerical simulation of the wind turbine in manageable computational time, simplifying assumptions were made and the validity of these assumptions was verified by simulating the flow over the S809 airfoil of the NREL turbine. In a dry environment, simulation of turbine power output agreed well with NREL experimental data. Our multiphase model showed that the rain film accumulation and flow on the surface of the turbine airfoil reduces the power output of the turbine. Figure 7. Time-averaged lift and drag coefficients for two rainfall rates of 40 and 400 mm/h at 08 to 208 angles of attack.

Aerodynamic Characteristics of Wind Turbines Operating under Hazard Environmental Conditions: A Review

“…At higher rainfall rates, the lift coefficient is higher compared to the no-rain case but accompanied by an unfavorable increase in the drag coefficient. Arastoopour and Cohan [112] refined their previous CFD model [111] to more effectively simulate the transfer of momentum during the formation of water films on the airfoils of a HAWT. The 2D airfoil simulation demonstrated an increase in the lift coefficient with the AOA, surpassing the stall angle observed in the single-phase case.…”

Aerodynamic Performance of Wind Turbines Operating under Hazard Environmental Conditions: A Review

“…Arastoopour and Cohan [112] refined their previous CFD model [111], to more effectively simulate the transfer of momentum during the formation of water films on the airfoils of a HAWT. The 2D airfoil simulation demonstrated an increase in the lift coefficient with the angle of attack, surpassing the stall angle observed in the single-phase case.…”