Since typical industrial-scale reactors may contain many millions of bubbles, the extension of direct free-surface modelling techniques to resolve every bubble in the vessel would require far more computational power than will be available. A more immediate solution is to couple macro-scale reactor models to micro-scale models of individual bubbles and collections of a small number of bubbles. ...

A liquid jet upon atomization breaks up into small droplets that are orders of magnitude smaller than its diameter. Direct numerical simulations of atomization are exceedingly expensive computationally. Thus, the need to perform multiscale simulations. In the present study, we performed multiscale simulations of primary atomization using a Volume-of-Fluid (VOF) algorithm coupled with a two-way ...

This work is a continuation of experimental and computational studies of the internal flow field of a large-scale Danfoss atomizer presented at an earlier ILASS conference [1,2]. Fluent 6.1 is used to simulate the flow through the large-scale atomizer. The two-phase flow is modeled using three approaches: 1) a volume of fluid (VOF) method using a laminar flow assumption, 2) a VOF method using l...

Low-capillary number or surface tension dominated flows are found in a number applications, ranging from small scale microfluidics up to larger scale analysis of microgravity sloshing. This paper evaluates the possibility of modelling of surface tension dominated multiphase flows using an Eulerian volume-of-fluid (VOF) approach with high-resolution surface capturing. With the aim of improved st...

The continuum surface force (CSF) method has been extensively employed in the volume-of-fluid (VOF), level set (LS) and front tracking methods to model the surface tension force. It is a robust method requiring relatively easy implementation. However, it is known to generate spurious currents near the interface, which may lead to disastrous interface instabilities and failures of grid convergen...

In this work incompressible two-phase flows are considered. The aim is to model high density-ratio flows with arbitrary complex interface topologies, such as occur in air/water flows. Between the phases a sharp front exists, where density and viscosity change abruptly. The computational method used in this paper is the Mass Conserving Level-Set method. It is based on the Level-Set methodology, ...

The understanding of polymeric fluids flows is of essential importance for several industry sectors, including plastic and food processing industries. The rheological response of viscoelastic fluids is quite complex, including combination of viscous and elastic effects and highly non-linear viscous and elastic phenomena. In a previous work we presented a solver for internal viscoelastic fluid f...

The paper is concerned with experimental investigations and numerical simulations of immiscible flows in microchannels in the presence of interfacial surface tension. The aim of the present study is to model the unsteady dynamics of the vortical structures and interface shape in the Y-branching geometries with square cross-sections. The tested fluids are Newtonian and weakly elastic polyacrylam...