Modeling of submicron particle transport based on VOF-LPT method

Abstract

The submicron particle transport inside a single bubble rising in water is investigated by the VOF-LPT method. As an improvement of the previous particle transport assumption in numerical studies, a new interfacial penetration model is developed according to the observed particle behavior in experimental works. The new criterion, namely particle Weber number is derived based on the dimensional analysis of the kinetic energy equation. The developed model is calibrated and evaluated based on the experimental data and parametric studies including particle size, density and gas–liquid surface tension are performed. The results indicated that the consideration of the interfacial penetration model is reasonable due to the presence of particle interfacial behavior dominant by surface tension force. The application of particle Weber number as the criterion is found to agree well with the experimental observations from both quantitative and qualitative aspects. In the presence of large particle inertia, the particle may deviate from the gas streamline and impact the bubble surface on one side, while the particle presents enhanced penetration capacity through the gas–liquid interface on the other side. With the decreasing gas–liquid surface tension, a competitive mechanism between the weakened internal flow and the enhanced penetration capacity is found, which complexes the effect of surface tension on particle transport in a non-monotonic way. In general, the interfacial penetration model developed in this study is proven to be feasible to describe submicron particle transport inside the rising bubble.