We investigated the transient behavior of immiscible two-liquid interfaces initiated by a single rising gas bubble and characterized by liquid "column" and "film" morphologies. To analyze the effect of the buoyancy force, viscosity, and interfacial tension on these morphologies, the single-solution density was controlled continuously by association with the rising velocity of the bubble. It was observed that the extension of the liquid column further into the upper liquid phase owing to the wake flow under the bubble is driven by the buoyancy force, with the velocity decreasing gradually with the distance between the bubble and the liquid-liquid interface. Based on this mechanism, we determined that a strong dimensionless correlation exists between the lifetime of the column and the physical properties of the two liquid phases. On the other hand, gravitational drainage does not affect the film lifetime. However, marginal pinching is dominant, probably owing to the existence of a surface tension gradient between the film and the meniscus.

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We performed a numerical analysis for simulating granular media structures containing non‐spherical elements and the liquid trickle flow characteristics of such structures. Fully‐Lagrangian numerical simulation methods can track all motion information for solid or liquid elements at each point in time. We introduced suitable compressibility to moving particle semi‐implicit (MPS) and performed individual packing behavior calculations for non‐spherical elements, based on discrete element method (DEM) with expanded functions. Rigid bodies‐DEM is a method using a DEM contact force model that is expanded to handle the motion of freely shaped solids. It expresses complex shapes to enable low calculation costs and intuitive mounting. We used the boundary for the granular media configured with non‐spherical elements to implement a trickle flow simulation based on weakly compressible‐MPS. Even for elements of equal volume, different shapes changed the liquid passage velocity and hold‐up amount. The mean downflow velocity of the liquid phase was not always dependent on the void fraction. For the plane of projection, we obtained a good correlation with the mean downflow velocity in each packed structure, and successfully performed arrangements according to the new liquid‐passage shape coefficient. © 2016 American Institute of Chemical Engineers AIChE J, 63: 2257–2271, 2017

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The interfacial behavior between sodium polytungstate solution (SPTS) and silicone oil (SO) due to a single rising bubble was directly observed to investigate the influence of the Eötvös number on the flow characteristics. We found that the transient behavior of the jet under the bubble strongly depended on the SPTS density in the range of 1 000-3 000 kg/m 3. Although the SPTS film generated in the SO influenced the detention time of the jet under the bubble, the lifetime of the film did not depend on the SPTS density.

17The behavior of the interface between molten Sn and the LiCl-KCl eutectic 18 melt system was observed directly. We found that the transient behavior of the interface 19 exhibits considerable temperature dependence through a change in its physical 20 properties. The "metal film" generated in the upper molten-salt phase significantly 21 influences the shape of the interface. Although the lifetime of the metal film depends on 22 the gas flow rate, it is not affected by the buoyancy if the interfacial tension is dominant. Most extractive metallurgical treatments produce a two-liquid-phase system 1 consisting of a metal-rich phase and a less-dense slag phase. The main purpose of such 2 processes is to concentrate the metal phase into a form suitable for further refining and 3 to efficiently remove the gangue materials as a molten slag. Gaseous phases, which are 4 introduced into the liquid metal phase or produced there by reactions, pass through the 5 metal-slag interface. As this happens, the rising gas bubbles might entrain the heavier 6 liquid metal from the bottom layer into the top layer of the lighter molten slag. This 7 will be either desirable or detrimental, depending on the application in question. In bursting in the gas-slag-iron system was investigated using the X-ray transmission 23 technique [13][14][15][16][17]. These studies found two mechanisms for droplet formation, namely, 24 jet entrainment and film entrainment. Nevertheless, in-situ X-ray observations of the 25 dynamic behavior of the molten metal-slag interface have also proven difficult, owing 26 to the extremely limited observation domain. That is to say, the behavior of a 27 three-dimensional bubble cannot be clarified from a two-dimensional image analysis. 28To understand the dynamic behavior of a liquid-liquid-gas interface, direct the Sn-salt interface (t = 0.12 s) and started to disperse, penetrating the upper phase. 16The reason for this could be that, because of the lack of a buoyancy force, the gas