Wind tunnel testing of a swept tip shape and comparison with multi-fidelity aerodynamic simulations

Abstract. One promising design solution for increasing the efficiency of modern horizontal axis wind turbines is installation curved tip extensions. However, introducing such complex geometries may move traditional aerodynamic models based on blade element momentum (BEM) theory out their range applicability. This motivated present work, where a swept shape investigated by means both experimental and numerical tests. The latter group accounted wide variety models, allowing us to highlight capabilities limitations each them in relative manner. considered result optimization, focusing locally maximizing power performance within load constraints. For tests, model instrumented with spanwise bands pressure sensors tested Poul la Cour tunnel at Technical University Denmark (DTU). methods used tests consisted model, near-wake lifting-line free-wake fully resolved Navier–Stokes solver. comparison test results performed given angles attack speeds, which representative expected conditions operation. Results show that cannot predict measured normal force coefficients, but other are generally good agreement measurements attached flow. Flow visualization distribution compare well computational fluid dynamics (CFD) simulations. clean case better than tripped inboard sections. Some uncertainties regarding effect boundary layer wall post-stall behavior remain.