Effect of Airfoil Geometry on Performance with Simulated Intercycle Ice Accretions
Andy P. Broeren and Michael B. Bragg
University of Illinois, Urbana, Illinois, 61801
ABSTRACT
This paper presents the results of an experimental study designed
to evaluate the performance effects of intercycle ice accretions on airfoils
with different geometries. The intercycle ice accretions were simulated using
combinations of various size grit roughness. These simulations were tested
on three airfoils: NACA 23012, NACA 3415 and NLF 0414 at a Reynolds number
of 1.8x106 and a Mach number of 0.18. Results from the NACA 23012
airfoil tests closely matched those from a previous study, validating the
ice-shape simulation method. This also showed that a simple geometric (chord-based)
scaling of the ice was appropriate. The simulated ice effect, in terms of
maximum lift performance, was most severe for the NACA 23012 airfoil. The
maximum lift coefficients were in the range of 0.65 to 0.80 for the iced
configuration compared to a clean value of 1.47 for the NACA 23012 airfoil
at this Reynolds number. In contrast, the maximum lift coefficients for the
NLF 0414 airfoil with the same ice simulations were in the range of 0.90
to 1.05, compared to a clean value of 1.34. The results for the NACA 3415
with the simulated intercycle ice shapes were between the other two airfoils.