On the formation of dry granular jets at a liquid surface

This work considers the effects of various parameters, including grain wettability (contact angle), density, size, mass flow rate and impact velocity, on the formation of dry granular jets when grains are poured onto a liquid surface. By comparing the ratio of the kinetic energy of the grains and the surface energy needed to create the granular jet (dE(S)), it is found that the transition between island formation and jetting occurs when dE(k)/dE(S) > 1.50. Principally, jet formation depends on the kinetic energy of the grains when impacting the surface, and the grain wettability. Conditions have been identified under which a jet of dry grains containing entrained air is formed in the liquid, which additionally suggests how this can potentially be avoided in grain dispersion applications. (C) 2021 Published by Elsevier Ltd.