Comparison between RANS simulations and assumptions adopted by a semi-empirical dynamic stall model

Abstract

The dynamic stall is responsible for a significant excess of aerodynamic load on wind-turbine and helicopter blades. Such high dynamical load may cause the failure of these systems through fatigue. Semi-empirical dynamic stall models are widely used both for blade design and investigations of their structural behavior. Therefore, improvements of these models are of fundamental importance for the design more reliable blades. The proposed research aims at comparing the solution of a computational-fluid-dynamics (CFD) tool for the flow over a pitching airfoil with hypothesis considered by a widely used semi-empirical dynamic-stall model. Particularly, the criterion for stall onset and the stall vortex speed assumed by the Beddoes-Leishman model will be compared with the flow predicted by CFD simulations. It is hoped that the research can substantiate improvements to semi-empirical, dynamic stall models.