How should the lift and drag forces be calculated from 2-D airfoil data for dihedral or coned wind turbine blades?

Abstract. In the present work, a consistent method for calculating lift and drag forces from 2-D airfoil data dihedral or coned horizontal-axis wind turbines when using generalized lifting-line methods is described. The refer to models that discretize blade radially into sections use data, example, (LL), actuator line (AL), element momentum (BEM) vortex cylinder (BEVC) methods. A interpretation of classic unsteady thin theory results reveals it necessary both relative flow information at one point on chord chordwise gradient direction correctly determine aerodynamic force moment. Equivalently, magnitude should be determined by three-quarter-chord point, while quarter-chord point. However, this aspect generally overlooked, most implementations in only calculation per section simplicity. This simplification will not change performance prediction planar rotors but cause an error applied non-planar rotors. work effect investigated special case, where turbine has out-of-plane shapes (blade dihedral) no in-plane sweep), operating under steady-state conditions with uniform inflow perpendicular rotor plane. impact comparing predictions approach LL simplified one-point approaches. are verified blade-geometry-resolving Reynolds-averaged Navier–Stokes (RANS) simulations. numerical investigations confirmed full complying sectional loads upwind- downwind-coned blades calculated method, BEM BEVC AL compared method. Results including different specific implementation schemes, shown agree significantly better fully resolved RANS than often used