Computational investigation of simulated large-droplet ice shapes on airfoil aerodynamics

The objective of this research was to study numerically the effects of simu lated spanwise-step-ice accretions (resulting from supercooled large-drople t icing conditions) on subsonic aircraft aerodynamics. The investigation wa s performed with a high-resolution full Navier-Stokes code with a solution- adaptive unstructured grid for both non-iced and iced configurations. The a irfoil investigated was a modified NACA 23012 with a simple flap. Simulated ice shapes were tested on the airfoil to determine the sensitivity of ice shape sire on airfoil performance and control. Predictions of sectional aer odynamic characteristics for quarter-round ice shape heights of 0.0083 and 0.0139 chords are presented and compared with experimental data. Significan t reductions in lift were noted for these relatively small protuberances, w hich were consistent with experimental findings. The results also indicate good predictive performance for drag, pitching-moment, and hinge-moment var iations.