Numerical study of droplet behavior passing through a constricted square channel

Gu，Qingqing1; Zhang，Jinggang2; Liu，Haihu3; Wu，Lei4

2023-07-01

10.1063/5.0160082

Physics of Fluids   Impact Factor & Quartile

1070-6631

1089-7666

Snap-off is a crucial mechanism for drop breakup in multiphase flow within porous media. However, the systematic investigation of snap-off dynamics in constricted capillaries with varying pore and throat heights remains limited. In this study, we conducted three-dimensional simulations of drop behavior in a constricted square capillary with non-uniform depth, employing a color-gradient lattice Boltzmann model. Our analysis encompassed a comprehensive range of parameters, including geometrical factors and physical properties, such as capillary number, initial drop size, viscosity ratio, constriction length, and the presence of soluble surfactants. Depending on these parameters, the drop exhibited either breakup or deformation as it traversed the constriction. Upon snap-off occurrence, we quantified two significant aspects: the snap-off time t ̂ b , which represents the time interval between the drop front passing the constriction center and the snap-off event, and the volume of the first daughter drop V ̂ d generated by the breakup mechanism. Consistently, we observed a power-law relationship between t ̂ b and the capillary number Ca. However, the variation of V ̂ d with Ca exhibited a more complex behavior, influenced by additional factors, such as the viscosity ratio and the presence of surfactants, which break the linear increase in V ̂ d with Ca. Notably, the inclusion of surfactants is able to homogenize the volume of the first daughter drop. Through our comprehensive numerical study, we provide valuable insight into the snap-off process in constricted capillaries. This research contributes to the understanding of multiphase flow behavior and facilitates the optimization of processes involving snap-off in porous media.

SCI

English

Others

National Natural Science Foundation of China[12072257] ; Major Special Science and Technology Project of the Inner Mongolia Autonomous Region[2020ZD0022] ; Shanghai Pujiang Program[22PJD047]

Mechanics ; Physics

Mechanics ; Physics, Fluids & Plasmas

WOS:001034275700004

AIP Publishing

PHYSICS

2-s2.0-85166116642

Scopus

1.School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai,200093,China
2.School of Building Services Science and Engineering,Xi'an University of Architecture and Technology,Xi'an,710055,China
3.School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an,28 West Xianning Road,710049,China
4.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Gu，Qingqing,Zhang，Jinggang,Liu，Haihu,et al. Numerical study of droplet behavior passing through a constricted square channel[J]. Physics of Fluids,2023,35(7).

Gu，Qingqing,Zhang，Jinggang,Liu，Haihu,&Wu，Lei.(2023).Numerical study of droplet behavior passing through a constricted square channel.Physics of Fluids,35(7).

Gu，Qingqing,et al."Numerical study of droplet behavior passing through a constricted square channel".Physics of Fluids 35.7(2023).