Shear Adhesion of Ice on Large-Sized Grooved Aluminum Surfaces

Iceadhesion is important when designing aircraft anti-icing/de-icingsystems. Major and minor grooves are common in the skin of aircraft.However, the effects of millimeter-scale grooves on ice adhesive strengthhave not been given due attention. Specimens with varying depths,widths, and numbers of grooves were fabricated by machining to investigatethe ice adhesive characteristics of large-sized grooved aluminum surfaces.After the ice cube was frozen on the surface using a silicon mold,the adhesive force was measured using a self-assembled shear adhesiveforce setup. A correlation between groove size and apparent adhesivestrength in the perpendicular loading direction was established basedon the experimental results. Every 1% increase in the groove widthratio was associated with an 18.7 kPa increase in apparent adhesivestrength. The increasing speed of the adhesion rapidly decayed asthe groove depth increased. The increase in adhesion reached 99% ofthe maximum increase when the groove depth reached 0.8 times the width.The number of grooves had little effect on the adhesion when the totalwidth of the grooves was kept constant. Stress distribution analysiswas conducted using the finite element method, and the results werein accordance with the cracking phenomena in the experiments. Theadhesive strength in the parallel loading direction was 30% lowerthan that in the perpendicular loading direction for all six chosensurfaces. This study is the first to propose a quantitative relationshipbetween the surface textures of millimeter-sized grooves and ice adhesivestrength. The loading orientation also had a substantial influenceon adhesion. The results will serve as a valuable reference for futurestudies on ice adhesion on textured surfaces and for improving theperformance of anti-icing/de-icing systems.