Effect of Ice Accretion Simulation Fidelity on Low-Reynolds Number Swept-Wing Aerodynamic Performance

Abstract

Understanding how ice accretion affects the aerodynamics of swept-wing aircraft is a vital part of aircraft design, fabrication, and testing. Previous work focused on iced airfoil aerodynamics which did not take into account the geometric complexities of a swept wing. A method to create a series of full-span artificial ice shapes for a swept wing was developed so aerodynamic testing could be performed for a variety of ice shapes. Due to icing scaling limitations and icing wind tunnel size restrictions, ice accretions could not be produced for the full span of a swept wing. Instead, ice was accreted for small sections of the leading edge, laser scanned, and digitally manipulated to manufacture a full-span artificial ice shape. These full-span artificial ice shapes were used in low Reynolds number experimental testing. Wind tunnel testing was performed at Reynolds numbers of 1.8 x 106, 1.6 x 106, and 2.4 x 106 and Mach numbers of 0.09, 0.18, and 0.27, respectively, for model angles of attack ranging from -6 to 16. The swept-wing model used was a scaled version of the NASA Common Research Model wing, which is representative of modern commercial airliner. Force balance, oil-flow visualization, fluorescent mini-tuft visualization, and surface pressure data were collected for 18 leading-edge configurations including 7 high-fidelity ice shapes, 10 low-fidelity versions of these ice shapes, and the clean leading edge without artificial ice shapes present. The goal of this study is to determine how each artificial ice shape configuration affects the aerodynamic performance of the swept-wing model and the role ice shape simulation fidelity plays.