A New Stall Delay Model for HAWT Based on Inviscid Theory

Abstract

Aeroelastic analysis of wind turbine blade is one of the most important studies, which is a typical phenomenon of the fluid–structure interaction. In order to increase the accuracy of the aeroelastic analysis, in this paper, we developed a new three-dimensional (3D) stall delay model for horizontal axis wind turbine (HAWT), which is inviscid stall delay model (ISDM). The model is derived from the Navier–Stokes equations, in which we treat the stall delay effects differently by the delay of the separation point on the airfoil, and aim to capture the further negative pressure reduction in the separation area due to the span wise flow driven by the centrifugal force on the rotating blade. Based on the analytical solution, the ISDM is created and the correction factor S is analyzed. In order to validate ISDM, the model is applied to the NREL Phase VI wind turbine blade. Both the corrected lift and drag coefficients and the power/torque results are compared with the experimental data. From the comparison it can be concluded that ISDM gives reasonable predictions of the 3D lift and drag coefficients as well as the corresponding power and thrust force obtained from blade element and moment (BEM) computation.