Large fragmentation under drop suspension splashing

In our work, we first experimentally checked whether the existing splashing criteria would work for droplets of dilute suspensions with particles 10 mu m in diameter. The suspensions were a mixture of aqueous glucose solution with isodense hydrophilic polystyrene particles. The drop splashing of the suspensions began at lower impact velocities than for pure water under the impact onto hydrophilic flat glass substrates. The splashing of such suspensions could not be described by any of the existing criteria - neither for a pure liquid with effective viscosity nor by using criteria that consider the energy balance of separately escaping particles. Analysis of the escaping fragments showed that their diameter was an order of magnitude larger than the particles' diameter. Taking into account the size of the escaping fragments in the criterion based on energy balance allowed to predict the splashing of the considered suspensions. (C) 2019 Elsevier Ltd. All rights reserved.