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

Abstract

Abstract The study of wind turbine wakes is very important for the layout of offshore wind farms. In recent years, the method of reducing the influence on the downstream turbines by setting yaw angles of the upstream wind turbine has received constant attention. In this paper, a numerical method based on OpenFOAM solver combined with an improved actuator line method is applied to study the wake interactions between yaw wind turbine and downstream wind turbine. The improvement of the actuator line method mainly includes two aspects, which are, Gaussian anisotropic body force projection method and integral velocity sampling method. Numerical accuracy is validated with a benchmark wind turbine model (NREL 5MW wind turbine), which provided a certain accuracy guarantee for the wake prediction of the tandem arranged wind turbines. And then, the wake effects from upstream turbine in no yaw condition is simulated, which has good agreements with the published result in the literature. Based on these precision verification efforts, finally, this paper makes a series of predictions of the power coefficients and wake characteristics of two tandem arranged wind turbines in different yaw angles.