Aerodynamics of a Swept Wing With Simulated Scalloped Ice at Low Reynolds Number

Abstract

This thesis studied the aerodynamic effects of a single high-fidelity scalloped ice accretion simulation and a low-fidelity simulation of the same shape. These data were compared to the aerodynamics of a clean 8.9% scale CRM65 semispan wing model at a Reynolds number of 1.6×10^6. The clean wing experienced an aggressive, tip-first stall and showed a small, strong leading-edge vortex at lower angles-of-attack while the iced cases showed larger, seemingly weaker leading-edge vortices at similar angles. The size of these vortices is larger for the low-fidelity ice shape. The stall pattern for the iced cases was also tip-first, but more gradual than the clean wing. The high-fidelity ice shape produced streamwise flow features over the upper surface of the wing likely due, in part, to flow moving through gaps that exist in the ice shape geometry that disrupted the formation of the leading-edge vortices. These features are thought to change the aerodynamics of the wing by impacting leading-edge vortex formation and delaying flow separation. These gaps do not exist in the low-fidelity shape, where leading-edge vortices are larger, are apparent at lower angles-of-attack, and flow separation occurs earlier over the wing. The low-fidelity scallop ice shape was non-conservative in its aerodynamic performance penalties compared to the full high-fidelity case.