Fine Structure of the Distribution of the Matter of a Coal Slurry Drop in Water in Intrusive and Impact Confluence Regimes

The methods of high-speed videorecording are applied for the first time to trace the evolution of the fine structure of the distribution of the free-falling coal slurry matter in a cuvette filled by tap water in different flow regimes. Multi-point illumination is used to reduce the unwanted light and the effect of complete internal reflection. In intrusive regime at small contact velocities, when the kinetic energy of the drop (KRD) is smaller than its potential surface energy (PSE), the drop of heavier suspension flowing smoothly into a receiving fluid forms a lenticular intrusion. The submerging intrusion transforms gradually into a vortex ring, which breaks down gradually into systems of new vortex rings, as in the classical experiments of J.J.Thomson and H.F. Newell. In the impact regime, where the ratio of the energy components is inverse, a confluent drop of the suspension deforms the fluid surface and breaks down into slender jetlets, whose traces form colored lineate structures and reticular formations on the fluid surface and within its thickness. The vortical head walls of the jetlets are slowly enlarged in motion and form colored ringlets after their stoppage. The suspension descents on the cavity bottom and penetrates into the fluid thickness, where it is gathered in an intermediate layer and distributed in a system of loops beneath the collapsing cavity. The pattern of the carbon microparticle distribution restructures itself rapidly with further flow evolution, as in the case of the confluence of an electrolyte drop.