A computationally efficient engineering aerodynamic model for swept wind turbine blades

Abstract. In this work, a computationally efficient engineering model for the aerodynamics of swept wind turbine blades is proposed extended blade element momentum (BEM) formulation. The modified based on coupled near- and far-wake model, in which near wake assumed to be first quarter revolution non-expanding helical own blade. For special case in-plane trailed vorticity, original empirical equations determining steady-state value near-wake induction are replaced by analytical results, form incomplete elliptic integrals. general condition vorticities, approximated results conditions correction factor. factor calculated using with influence coefficient tensors, minimize computational effort. These tensors pre-calculated fitted from numerical integration Biot–Savart law. With indicial function approach, it not necessary explicitly save information vorticities that were previous time steps. This approach combination approximations, low constant effort each step. practically applicable time-marching aero-servo-elastic simulations. uniform inflow perpendicular rotor compared BEM code, lifting-line solver Navier–Stokes solver. significantly improved agreement higher-fidelity models method highlights performance method.