Investigation of Different Droplet Formation Regimes in a T-junction Microchannel Using the VOF Technique in OpenFOAM

Malekzadeh, Shima; Roohi, Ehsan

doi:10.1007/s12217-015-9440-2

Cited by 60 publications

(25 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dynamics of droplet formation in a second fluid inside microchannels have important applications in drug delivery (Richter et al, 1997), food industries (Cal, 2005), mixing in microfluidic multiphase systems (Losey et al, 2002), and a wide range of applications in biology and chemistry. Monodisperse droplets can be generated via different methods in microfluidic devices, including cross-junction devices Brazilian Journal of Chemical Engineering (Yasuno et al, 2004;Sugiura et al, 2004;Elzanfaly et al, 2015) , T-junctions (Cheng et al, 2016;Liu et al, 2015;Sbragaglia et al, 2016;Thorsen et al, 2001;Nisisako et al, 2002;Xu et al, 2006;Garstecki et al, 2006;Van der Graaf et al, 2006;Christopher et al, 2008;Azarmanesh and Farhadi, 2015;Malekzadeh and Roohi, 2015), flow-focusing devices (Anna et al, 2003;Cubaud et al, 2005;Garstecki et al, 2005;Fu et al, 2009) and co-flowing devices (Umbanhowar et al, 2000;Hua et al, 2007;Alizadeh et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Different Stages of Liquid Film Growth in a Microchannel: Two-Phase Lattice Boltzmann Study

Nazari

Sani

Kayhani

et al. 2018

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

A free energy model is used to describe the droplet formation and break-up process in a T-junction bio-microchannel. Droplets are created as a result of interaction of two immiscible liquids. Different stages for the droplet formation process are analyzed which are: a) growing in the x and y directions, b) growing in the x direction and c) detachment process. The effects of capillary number and flow rate ratio on the droplet formation stages are also studied. The influences of Capillary number, flow rate ratio, viscosity ratio and geometrical parameters on droplet break up, droplet size and detachment time are systematically studied. By increasing the flow rate ratio; the duration of droplet formation and the length of the x-growth stage are decreased for small capillary numbers. For larger capillary numbers; the droplet penetrates toward the downstream; therefore, the length of the x-growth stage is increased. The start of detachment process in the microchannel is also reported, which is related to narrowing of the neck of the liquid film. The results show that the detachment time is increased by decreasing the Capillary number. For Ca>0.02, the detachment time is independent of the flow rate ratios. Moreover; the effects of viscosity ratios on detachment time are not significant in comparison to the effects of capillary number. For Ca<0.04, the size of the droplet is independent of the viscosity ratio, but after the critical Capillary number (i.e., Ca=0.04), the size of the droplet is varied by the viscosity ratio. The time between two consecutive drops is also decreased by increasing the Capillary number. Moreover, this time is decreased by increasing the flow rate ratio until Ca=0.04. After this Capillary number, the flow rate ratios have no significant effect on the time between two consecutive droplets. An exhaustive validation study is performed including (a) the Laplace equation in the stationary droplet; (b) a contact angle test; (c) Taylor deformation test in shear flow and (d) comparison of the droplet length as a function of flow rate ratio between the present work and other studies.

show abstract

Section: Introductionmentioning

confidence: 99%

Different Stages of Liquid Film Growth in a Microchannel: Two-Phase Lattice Boltzmann Study

Nazari

Sani

Kayhani

et al. 2018

Braz. J. Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…Also using a two-dimensional numerical model with Volume of Fluid method (VOF), the phenomena of alternating droplet formation, with applications such as nanoparticle synthesis, hydrogel bead generation, and cell transplantation in biomedical therapy, was studied by Ngo et al [7]. Malekzadeh & Roohi [8] focused in the twodimensional bubble formation process by analysing in detail the eects of three main parameters, that are: the capillary number, the contact angle and the gas-liquid ow rate ratio. As for 3D simulations, droplet formation in T-junction microchannels was studied using the Lattice Boltzmann method by Shi et al [9] and simulations in heat exchangers using the VOF method were performed by Ben Saad et al [10].…”

mentioning

confidence: 99%

Numerical Study and Experimental Comparison of Two-Phase Flow Generation in a T-Junction

Calderón¹,

Montlaur²

2017

AIAA Journal

View full text Add to dashboard Cite

“…Zhao et al [30] investigated the behavior of slug flow to prepare cryogel beads in a rectangular microchannel, and correlations of the liquid-liquid slug flow parameters were obtained for the bead diameter estimation. Malekzadeh et al [31] utilized the OpenFOAM code to simulate the droplet formation in a T-junction microchannel, and found that when the contact angle increased, the droplet detachment time increased in the slug flow regime, while it decreased in the dripping regime. Gupta et al [32] analyzed the effects of viscoelasticity on the liquid threads breakup in a cross-junction microchannel, by mesoscale lattice Boltzmann methods.…”

Section: Introductionmentioning

confidence: 99%

Effects of a Dynamic Injection Flow Rate on Slug Generation in a Cross-Junction Square Microchannel

Qian

Chen

et al. 2019

Processes

View full text Add to dashboard Cite

The injection flow rates of two liquid phases play a decisive role in the slug generation of the liquid-liquid slug flow. However, most injection flow rates so far have been constant. In order to investigate the effects of dynamic injection flow rates on the slug generation, including the slug size, separation distance and slug generation cycle time, a transient numerical model of a cross-junction square microchannel is established. The Volume of Fluid method is adopted to simulate the interface between two phases, i.e., butanol and water. The model is validated by experiments at a constant injection flow rate. Three different types of dynamic injection flow rates are applied for butanol, which are triangle, rectangular and sine wave flow rates. The dynamic injection flow rate cycles, which are related to the constant slug generation cycle time t0, are investigated. Results show that when the cycle of the disperse phase flow rate is larger than t0, the slug generation changes periodically, and the period is influenced by the cycle of the disperse phase flow rate. Among the three kinds of dynamic disperse flow rate, the rectangular wave influences the slug size most significantly, while the triangle wave influences the separation distance and the slug generation time more prominently.

show abstract

Investigation of Different Droplet Formation Regimes in a T-junction Microchannel Using the VOF Technique in OpenFOAM

Cited by 60 publications

References 16 publications

Different Stages of Liquid Film Growth in a Microchannel: Two-Phase Lattice Boltzmann Study

Different Stages of Liquid Film Growth in a Microchannel: Two-Phase Lattice Boltzmann Study

Numerical Study and Experimental Comparison of Two-Phase Flow Generation in a T-Junction

Effects of a Dynamic Injection Flow Rate on Slug Generation in a Cross-Junction Square Microchannel

Contact Info

Product

Resources

About