Blowing away a sticky particule

Adhesive surfaces tend to trap particles. However, when submitted to wind, the particles may be blown away. We present a model experiment where spherical beads deposited on a horizontal surface coated with a layer of viscous liquid is placed in a wind tunnel. Interestingly, the wind-induced motion of this sphere involves a combination of rolling and sliding. We will present how the steady velocity of the sphere depends on materials parameters and wind velocity. Different regimes are observed depending on the relative importance of capillary and gravitational forces. The experimental data are compared with a previous study of a sphere rolling down an incline [1] and we propose an empirical law compatible with both configurations.



[1] Bico, J. et al. “Rolling stones: The motion of a sphere down an inclined plane coated with a thin liquid film.” Physics of Fluids 21.8 (2009): 082103-8.