An open database of high-fidelity, multi-Reynolds airfoil polars for wind turbine blade design

Abstract

This paper presents an open-access dataset that has been developed to provide high-fidelity aerodynamic polars for a wide range of wind turbine airfoils, computed using a consistent computational fluid dynamics (CFD) methodology. The database includes lift, drag, and moment coefficients across multiple Reynolds and Mach numbers. Coefficients are computed with both fully turbulent and free transition boundary layers between positive and negative stall angles. A blend of the free transition and fully turbulent coefficients is also included. Beyond the stall region, state-of-the-art post-stall extrapolation models are used, the calibration parameters of which are derived from a number of high-fidelity calculations at various angles of attack in separated flow. The data are relevant for wind turbine design, modeling, and simulation and reflect representative airfoil performance along the span of modern, large-size offshore rotors. The database includes FFA-W3, FFA-W2, FFA-W1, DU, FX-77, and the recently developed OSO families of airfoils. All simulations are performed using validated numerical methods and span a range of conditions typical of utility-scale offshore turbines. The paper discusses the dataset and its key differences from other open-access data, as well as some general trends that can be noted in the aerodynamic coefficients; such a discussion is made possible by the volume of data produced and is specifically tailored to wind turbine applications.