Experimental analysis of a horizontal-axis wind turbine with swept blades using PIV data

Abstract

This study presents findings from a wind tunnel experiment investigating a model wind turbine equipped with aft-swept blades. Utilising particle image velocimetry, velocity fields were measured at multiple radial stations. These allow the derivation of blade-level aerodynamic parameters, including bound circulation, induction values, inflow angle, angle of attack, and forces normal and tangential to the rotor plane. The measured local lift coefficient aligns well with the lift polar of the design airfoil, validating the experimental approach. The resulting public dataset provides a comprehensive aerodynamic characterisation of rotating swept blades in controlled conditions. It can serve as a baseline for future experimental research on swept wind turbine blades. Furthermore, it is valuable in validating numerical models of varying fidelity simulating swept wind turbine blades. The provided blade-level aerodynamics are particularly relevant to lower-fidelity models such as blade element momentum theory and lifting-line algorithms. At the same time, the measured flow fields can be compared against higher-fidelity simulation results from computational fluid dynamics.