Evolution of the Leading-Edge Vortex on a Revolving Wing and its Effect on Aerodynamic Loading

The leading-edge vortex (LEV) plays a dominant role in the aerodynamic loading of wings in many configurations, but particularly so for wings undergoing dynamic motion such as for pitching, revolving or flapping wings. While a growing LEV can generate a high lift force, it can also be a precursor to dynamic stall. For revolving wings, additional forces such as centripetal and Coriolis forces affect the stability and evolution of the LEV, and these mechanisms are far from being well understood. In the present study, the evolution of the LEV on a two bladed rotor, and its effect on the aerodynamic forces are investigated by performing high-fidelity, direct numerical simulations. The Reynolds number based on the chord and tip-velocity is 5000, and the simulations are designed to match experiments that employ 3D PIV measurements. The mechanisms for the LEV instability and shedding, and their effects on the aerodynamic forces are analyzed by applying a Force Partitioning Method (Menon & Mittal, JFM, Vol. 918, 2021), which enables precise quantification of the effect of the LEV and other vortices on the aerodynamic loading of the revolving wing.