Study on droplet breakup behaviors in 3-D pore-throat microchannel

doi:10.11949/0438-1157.20190652

Abstract

Abstract:

The flow behaviors of droplets breakup in the three-dimensional (3-D) pore-throat microchannel were investigated using a high-speed camera. A glycerin-water solution of different viscosity was used as a dispersed phase, and a mineral oil containing 4%(mass) of a surfactant (Span 20) was used as a continuous phase. Three flow patterns were observed when the droplets flowed out the pore-throat structure: spherical breakup, non-spherical breakup and non-breakup. Except extremely low capillary number of continuous phase, the increase of the viscosity of the dispersed phase or two-phase flow rates is not conducive to droplet breakup. Generally, the breakup position of the droplets approaches to the throat outlet. The spherical breakup of the droplets was further studied, the results indicate that the average daughter droplets size decreases with the increase of the viscosity of the dispersed phase and the flow rate of the continuous phase. The variation of the average size of daughter droplets with capillary number could be scaled with a power-law relationship, and the predicted result agrees well with the experimental data.

Key words: 3-D pore-throat structure, droplet, breakup, microchannel, two-phase flow, microfluidics

摘要：

利用高速摄像仪研究了三维孔喉结构微通道内液滴的破裂行为。采用不同黏度的甘油-水溶液作为分散相，含4%（质量）表面活性剂（Span 20）的矿物油作为连续相。液滴通过孔喉结构后，观察到了三种流型：球形破裂、非球形破裂和不破裂。除极低连续相毛细数的情形外，分散相黏度和两相流量的增加不利于液滴破裂，液滴的破裂位置均接近于喉道出口。研究了液滴的球形破裂，结果表明，球形破裂中子液滴平均尺寸随分散相黏度和连续相流量的增加而降低，且与两相总毛细数呈幂律关系，模型预测值与实验结果吻合良好。

关键词: 三维孔喉结构, 液滴, 破裂, 微通道, 两相流, 微流体学

CLC Number:

TQ 021.1

Hao ZHOU, Chunying ZHU, Taotao FU, Xiqun GAO, Youguang MA. Study on droplet breakup behaviors in 3-D pore-throat microchannel[J]. CIESC Journal, 2019, 70(10): 3924-3931.

周灏, 朱春英, 付涛涛, 高习群, 马友光. 三维孔喉结构微通道内液滴的破裂行为研究[J]. 化工学报, 2019, 70(10): 3924-3931.

Figures/Tables 9

Fig.1 Schematic diagram of experimental setup

Fig.2 3-D pore-throat microchannel

Table 1 Physical properties of liquids used in experiment

Solution	Density, ρ/(kg·m^-3)	Viscosity, μ/(mPa·s)	Interface tension, σ/(mN·m^-1)
4% Span20/mineral oil	852.9	22.23
10% glycerol-water solution	1020.5	1.13	3.42
20% glycerol-water solution	1045.0	1.51	2.04
30% glycerol-water solution	1070.5	2.10	1.80

Fig.3 Droplet behaviors when passing through 3-D pore-throat microchannel

Fig.4 Definitions of parameters to characterize droplet breakup process

Fig.5 Diagrams for droplet behaviors in 3-D pore-throat microchannel

Fig.6 Changing trend of daughter droplet sizes with flow rate of continuous phase(insert: L/W ~ Ca)

Fig.7 Representative trajectories for droplet approaching throat convergence(Q c = 2 ml·h-1, Q d = 0.4 ml·h-1. Dispersed phase: 10% gly-water)

Fig.8 Comparison between predicted values and experimental data of daughter droplet sizes

References 31

1	骆广生, 王凯, 徐建鸿, 等 . 微化工系统内多相流动及其传递反应性能研究进展[J]. 化工学报, 2010, 61(7): 1621-1626.
	Luo G S , Wang K , Xu J H , et al . Multiphase flow, transport and reaction in micro-structured chemical systems[J]. CIESC Journal, 2010, 61(7): 1621-1626.
2	Rodriguez-Rodriguez J , Sevilla A , Martinez-Bazan C , et al . Generation of microbubbles with applications to industry and medicine[J]. Annual Review of Fluid Mechanics, 2015, 47(1): 405-429.
3	Whitesides G M . The origins and the future of microfluidics[J]. Nature, 2006, 442(7101): 368-373.
4	Sinton D . Energy: the microfluidic frontier[J]. Lab on a Chip, 2014, 14(17): 3127-3134.
5	Dressler O J , Casadevall I Solvas X , Demello A J . Chemical and biological dynamics using droplet-based microfluidics[J]. Annual Review of Analytical Chemistry, 2017, 10(1): 1-24.
6	Stephenson W , Donlin L T , Butler A , et al . Single-cell RNA-seq of rheumatoid arthritis synovial tissue using low-cost microfluidic instrumentation[J]. Nature Communications, 2018, 9(1): 791.
7	赵绍磊, 王灵宇, 吴送姑 . 药物多晶型的研究进展[J]. 化学工业与工程, 2018, 35(3): 12-21.
	Zhao S L , Wang L Y , Wu S G . Progress in the research of pharmaceutical polymorph[J]. Chemical Industry and Engineering, 2018,35(3): 12-21
8	Fu T , Ma Y , Funfschilling D , et al . Bubble formation and breakup mechanism in a microfluidic flow-focusing device[J]. Chemical Engineering Science, 2009, 64(10): 2392-2400.
9	张沁丹, 付涛涛, 朱春英, 等 . 十字聚焦型微通道内弹状液滴在黏弹性流体中的生成与尺寸预测[J]. 化工学报, 2016, 64(2): 504-511.
	Zhang Q D , Fu T T , Zhu C Y , et al . Formation and size prediction of slug droplet in viscoelastic fluid in flow-focusing microchannel[J]. CIESC Journal, 2015, 67(2): 504-511.
10	王彦, 王靖涛 . 微流控技术制备聚酰胺微胶囊的工艺研究[J]. 化学工业与工程, 2018, 36(5): 20-25.
	Wang Y , Wang J T . Preparation of polyamide microcapsules based on microfluidics[J]. Chemical Industry and Engineering, 2018, 35(6): 20-25.
11	Wang K , Lu Y , Yang L , et al . Microdroplet coalescences at microchannel junctions with different collision angles[J]. AIChE Journal, 2013, 59(2): 643-649.
12	Link D R , Anna S L , Weitz D A , et al . Geometrically mediated breakup of drops in microfluidic devices[J]. Physical Review Letters, 2004, 92(5): 054503.
13	Leshansky A M , Pismen L M . Breakup of drops in a microfluidic T junction[J]. Physics of Fluids, 2009, 21(2): 023303.
14	Wang X , Wang K , Riaud A , et al . Experimental study of liquid/liquid second-dispersion process in constrictive microchannels[J]. Chemical Engineering Journal, 2014, 254: 443-451.
15	Wang X , Zhu C , Wu Y , et al . Dynamics of bubble breakup with partly obstruction in a microfluidic T-junction[J]. Chemical Engineering Science, 2015, 132: 128-138.
16	Leshansky A M , Afkhami S , Jullien M C , et al . Obstructed breakup of slender drops in a microfluidic T junction[J]. Physical Review Letters, 2012, 108(26): 264502.
17	Hoang D A , Portela L M , Kleijn C R , et al . Dynamics of droplet breakup in a T-junction[J]. Journal of Fluid Mechanics, 2013, 717(1): R4.
18	Finke J H , Niemann S , Richter C , et al . Multiple orifices in customized microsystem high-pressure emulsification: the impact of design and counter pressure on homogenization efficiency[J]. Chemical Engineering Journal, 2014, 248: 107-121.
19	Dai C , Fang S , Wu Y , et al . Experimental study of bubble breakup process in non-Newtonian fluid in 3-D pore-throat microchannels[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2017, 535: 130-138.
20	Wu Y , Fang S , Dai C , et al . Investigation on bubble snap-off in 3-D pore-throat micro-structures[J]. Journal of Industrial and Engineering Chemistry, 2017, 54: 69-74.
21	Ma Y , Zheng M , Bah M G , et al . Effects of obstacle lengths on the asymmetric breakup of a droplet in a straight microchannel[J]. Chemical Engineering Science, 2018, 179: 104-114.
22	Yamada M , Doi S , Maenaka H , et al . Hydrodynamic control of droplet division in bifurcating microchannel and its application to particle synthesis[J]. Journal of Colloid and Interface Science, 2008, 321(2): 401-407.
23	Vecchiolla D , Giri V , Biswal S L . Bubble–bubble pinch-off in symmetric and asymmetric microfluidic expansion channels for ordered foam generation[J]. Soft Matter, 2018, 14(46): 9312-9325.
24	Xu K , Liang T , Zhu P , et al . A 2.5-D glass micromodel for investigation of multi-phase flow in porous media[J]. Lab on a Chip, 2017, 17(4): 640-646.
25	Finke J H , Schur J , Richter C , et al . The influence of customized geometries and process parameters on nanoemulsion and solid lipid nanoparticle production in microsystems[J]. Chemical Engineering Journal, 2012, 209: 126-137.
26	Shum H C , Sauret A , Fernandez-Nieves A , et al . Corrugated interfaces in multiphase core-annular flow[J]. Physics of Fluids, 2010, 22(8): 082002.
27	Roof J G . Snap-off of oil droplets in water-wet pores[J]. Society of Petroleum Engineers Journal, 1970, 10(1): 85-90.
28	Lenormand R , Zarcone C , Sarr A . Mechanisms of the displacement of one fluid by another in a network of capillary ducts[J]. Journal of Fluid Mechanics, 1983, 135: 337-353.
29	Rossen W R . Snap-off in constricted tubes and porous media[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2000, 166(1): 101-107.
30	Jullien M C , Tsang Mui Ching M J , Cohen C , et al . Droplet breakup in microfluidic T-junctions at small capillary numbers[J]. Physics of Fluids, 2009, 21(7): 072001.
31	Fu T , Ma Y , Funfschilling D , et al . Dynamics of bubble breakup in a microfluidic T-junction divergence[J]. Chemical Engineering Science, 2011, 66(18): 4184-4195.

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