Application of a Prescribed Wake Aerodynamic Prediction Scheme to Horizontal Axis Wind Turbines in Axial Flow

A new prescribed wake model for horizontal axis wind turbines (HAWT's) is presented. The model's wake geometry is derived from simple prescriptive functions, based on momentum theory, defining the three-dimensional wake development from the near to the far field. Whilst the work described herein, however, only considers steady axial flow conditions, the detailed model and the numerical procedures employed are the precursor to the yawed flow case, including full unsteady aerodynamic blade coefficients. Model validation is by comparison with both field data and results from a free wake model. The predictions from the prescribed wake model match those of its free wake counterpart. The extension of this base case to more complicated flow states is considered.