Trafi Publications 25-2013
Aalto University School of Engineering Department of Applied Mechanics
Effects of anti-icing treatment on wing section lift degradation was studied in Aalto University Low Speed Wind Tunnel during winter period 2012-13. Type II and Type IV fluids of one manufacturer were tested. Wind tunnel model used was a three element two dimensional rotating wing section with a chord of 0.65 m. Wind tunnel test section is 2 m x 2 m. Conducted tests consisted of take-off simulations with approximately linear acceleration up to speed of 60 m/s (120 kt).
Comparison between one-step and two-step deicing treatment showed no significant differences in fluid flow off properties. Diluted Type IV fluids (25%/75%) appeared to have almost equal aerodynamic effects as neat Type IV during the first 10 s after rotation. Type II fluid had unexpectedly more adverse effect on lift than thicker Type IV fluids. Effect of acceleration time on lift degradation is straightforward by delaying the lift degradation. Also the effect of real cold soaking frost was studied in case of a quite thin frost layer. Aerodynamic effects were significantly less than in case of anti-icing fluids.