| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 156138 | Chemical Engineering Science | 2011 | 10 Pages |
Asymmetric straight flow-through microchannel (MC) arrays are high-performance MC emulsification devices for stable mass production of uniform droplets. This paper presents computational fluid dynamics (CFD) simulation and analysis of the generation of soybean oil-in-water emulsion droplets via asymmetric straight flow-through MCs, each consisting of a microslot and a narrow MC. We also used CFD to investigate the effects of the channel size and the flow of the dispersed phase on MC emulsification using asymmetric straight flow-through MCs with a characteristic channel size of 5–400 μm. The overall shape of an oil–water interface and the time scale during droplet generation via a control asymmetric straight flow-through MC were appropriately simulated. Better insight was obtained on the flow profile of the two phases and the internal pressure balance of the dispersed phase during droplet generation. Comparison of the CFD and experiment results also provided insight into dynamic interfacial tension during droplet generation. Successful droplet generation was observed below a critical dispersed-phase velocity. In this case, the resultant droplet size was proportional to the channel size and was not sensitive to the dispersed-phase velocity applied. The maximum droplet generation rate per channel was inversely proportional to the channel size, unless the buoyancy force did not promote droplet detachment. The maximum droplet productivity per unit area of an asymmetric straight flow-through MC array was estimated to be constant, regardless of channel size.
Graphical abstractDroplet generation via asymmetric straight flow-through microchannels with a characteristic size of 5–400 μm was successfully simulated using computational fluid dynamics (CFD). Successful droplet generation occurred in the absence of the cross-flow of a continuous phase.Figure optionsDownload full-size imageDownload high-quality image (128 K)Download as PowerPoint slideHighlights► The whole droplet generation process via an asymmetric straight flow-through MC was reasonably modeled by CFD simulation. ► Insight was obtained on flow profile of two phases and internal pressure balance of dispersed phase during droplet generation. ► The detachment process during droplet generation can be divided into three important stages. ► The size of successfully generated droplets was proportional to channel size. ► The maximum droplet productivity per unit area was estimated to be independent of the channel size.
