The results, when compared with published data, establish WindGEAR firmly as a robust wind turbine nonlinear aeroelastic analysis tool in time-domain. An integrated MATLAB tool WindGEARincorporating the two coupled codes is developed to simulate the fully-coupled aeroelastic response of the NREL 5 MW wind turbine. A novel strategy ‘primes’ the aeroelastic solver by moderating the response of rotor in its acceleration phase. A comprehensive treatment of the aeroelastic computations within the restrictions imposed by the aerodynamic theory is presented with the aid of a ‘shadow’ frame of reference rotating rigidly with the deforming blades. Towards the aerodynamic side, Blade Element Momentum Theory enhanced with several important corrections is employed, along with a dynamic stall model that accounts for the unsteady effects. The structural description is Lagrangian, obviating the need for an explicit definition of centrifugal/coriolis forces. For computing the geometrically nonlinear deformations of the rotor blades, we employ Simo-Vu-Quoc’s geometrically exact finite-strain spatial rod model, which treats the displacements of the beam reference line and the rotations of the cross-section as configuration variables, without any restrictions on their magnitudes or those of the resulting 1-D strain measures. A methodology is presented to obtain the nonlinear aeroelastic response of horizontal axis wind turbines using accurate and computationally efficient aerodynamic and structural descriptions.

Freedom planet torque attacks