HAWT near-wake aerodynamics, part I : axial flow conditions

Abstract

An improved physical understanding of the rotor aerodynamics of a horizontal axis wind

turbine (HAWT) is required to reduce the uncertainties associated with today’s design

codes. Wind tunnel experiments contribute to increased knowledge and enable valida- tion and construction of models. The present study focuses on the near-wake of a model

HAWT in both axial and yawed flow conditions. At three downstream planes parallel to the

rotor plane, single-sensor hot-film traverses are made. The phase-locked unsteady three- dimensional flow velocity vector is determined by a novel data reduction method. A series

of two papers discusses the near-wake aerodynamics of a model HAWT. The main goals

are to obtain a detailed understanding of the near-wake development and to arrive at

a base for model construction and validation. The first paper presents the experimental

setup, data reduction and the results for the baseline case (axial flow conditions). In the

second paper, the results for the yawed flow cases are presented and the effect of yaw

misalignment on the near-wake development is discussed. Copyright