Controlling the rebound on a solid surface by varying impact angles of ellipsoidal drops

Abstract

Enhancing drop deposition on solid surfaces has received significant attention in various fields. Breaking the circular symmetry in typical impact dynamics has opportunities for altering the mass and momentum distributions significantly and improving the deposition. Here, we study the impact dynamics of ellipsoidal drops on nonwetted solid surfaces to reduce the bounce magnitude as a function of the impact angle and ellipticity. Experimental and numerical studies reveal that the ellipsoidal drop with the impact angle shows a strong reduction in the maximum bounce height, compared with the spherical drops. The oblique drop impact exhibits a remarkable feature of the off-axis aligning process caused by asymmetric retraction dynamics. Axial momentum analyses help us to interpret the underlying principle behind the peculiar retraction dynamics and establish a transition map of the rebound and deposition for varying angles and ellipticities. We believe that a breakup of the symmetry in the dynamics can provide practical implications for the control of drop deposition in diverse applications, such as spraying, coating, and cooling.