Study on boundary conditions of k-ε-fp turbulence model for wind turbine wake simulation

Abstract

ABSTRACT Wind turbine wake has a great impact on the power output and fatigue damage of the whole wind farm. As a result, wind turbine wake simulation has attracted attention from both researchers and engineers for decades, in which turbulence modeling is the key point. Among all the turbulence modeling methods for wind turbine wake, k − ε − f P , a RANS model proposed by Laan in 2015, can balance well between efficiency and accuracy. In the current research, the boundary conditions of k − ε − f P turbulence model have been studied comprehensively. It was found that the boundary conditions of the model are affected by the wind conditions of the actual wind turbine, resulting in poor simulation accuracy under high wind shear conditions. Five simulation cases have been carried and compared with field measurement results. It was found that the roughness length z 0 is the most important factor for the determination of boundary conditions. Considering the wind shear conditions around wind turbine rotor, a new determination method for roughness length z 0 of the ground has been constructed, which corrects the wind profile prediction under high wind shear conditions. This research will contribute to the micro-sitting of future large wind farms.