A Study of Offshore Wind Turbine Wake Effects in Yaw Conditions Using an Improved Actuator Line Method

Abstract

The study of wind turbine wakes is very important for the layout of offshore wind farms. The technique of regulating the yaw angles of the upstream wind turbine to lessen the influence on the downstream turbines has attracted continual attention in recent years. In this study, the wake interactions between a yaw wind turbine and a downstream wind turbine are investigated using a numerical technique based on the openfoam solver in conjunction with an improved actuator line method. The Gaussian anisotropic body force projection method and the integral velocity sampling method are the two fundamental components of the improvement of the actuator line method. The NREL 5-MW wind turbine benchmark model is used to test the numerical accuracy. The simulation of the wake effects from the upstream turbine in non-yawed conditions that follows has good agreement with the results that have been published in the literature. Finally, this work presents a number of predictions about the power coefficients and wake characteristics of two tandem-arranged wind turbines at various yaw angles based on these precise verification efforts. The results of the analysis in yaw conditions are used to derive the yaw wake characteristics and the optimal yaw angle range. As the yaw angle increases, the total power of the wind turbine increases and then decreases, and the upstream wake area decreases significantly. The total power reaches its maximum at 20–30 deg. The research content of this paper will provide an important reference for wind farm scheduling.