Experimental Investigation of Simulated Large-Droplet Ice Shapes on Airfoil Aerodynamics

An experimental investigation was conducted to study the aerodynamic effect of simulated supercooled largedroplet ice accretion on a modie ed NACA 23012 airfoil. Forward-facing quarter-round simulations with heightto-chord ratios of 0.0083 and 0.0139 were used at a Reynolds number of 1 :8 £ 10 6 . When the simulated ice was placed at critical chordwise locations, a long separation bubbleformed downstream of thesimulated ice shape and effectively eliminated the formation of a large leading-edge suction peak that was observed on the clean NACA 23012 airfoil. This resulted in a dramatic reduction in the maximum lift coefe cient, as low as 0.27, when the larger simulated ice shape was located at 12% chord. Because the airfoil loading distribution was severely altered, large changes in airfoil pitching moments and e ap-hinge moments were also observed.