Characterization of Ice Adhesion Strength Over Different Surfaces Pertinent to Aircraft Anti-/De-Icing

摘要

Aircraft icing is widely recognized as a significant hazard to aircraft operations in cold weather. A number of anti-/de-icing systems have been developed recently for aircraft icing mitigation and protection, which can generally be classified into two categories: active and passive methods. While active methods rely on energy input from an external system for the anti-/de-icing operation, passive methods take advantage of the physical properties of the surfaces to prevent ice formation and accretion. While there is no known passive system that can completely eliminate ice formation over the protected surfaces, passive anti-/de-icing methods, especially icephobic surface coatings, have been proved to be very helpful to mitigate the problematic effects of icing for various icing related applications.;In the present study, a comprehensive study was conducted to characterize ice adhesion strength over various surfaces by using a custom-built shear strength tester. The studied surfaces include recently developed functionalized surfaces like Slippery Liquid-Infused Porous Surfaces (SLIPS) and commercially-available surface coatings like HydrobeadRTM, NeverWetRTM ; polymer-based surfaces such as PMMA and PTFE, and conventional metals like aluminum and stainless steel. In addition, the static and dynamic contact angles for all the control surfaces were also measured in order to correlate the measured ice adhesion strength with the surface wettability. Furthermore, surface topography analysis was performed to acquire the 3-D surface profiles along with the averaged surface roughness in order to examine the effects of surface roughness on ice adhesion strength. Similarly, the ice adhesion strength was also analyzed at different temperatures (i.e., -5°C, -100C, -15°C and -20°C ) to reveal the temperature effects on the ice adhesion strength over hydrophilic and hydrophobic surfaces. The influence of the durability of surface coatings on the ice adhesion performance of hydro-/ice-phobic coatings was also investigated experimentally in the present study. In coordinating with the experimental study, a numerical analysis was also performed to explore/optimize experimental design paradigms to minimize the measurement uncertainties.