0
Research Papers: Heat and Mass Transfer

Mesoscopic Analysis of Dynamic Droplet Behavior on Wetted Flat and Grooved Surface for Low Viscosity Ratio

[+] Author and Article Information
Saurabh Bhardwaj

Department of Mechanical Engineering,
Indian Institute of Technology Guwahati,
Guwahati, Assam 781039, India

Amaresh Dalal

Department of Mechanical Engineering,
Indian Institute of Technology Guwahati,
Guwahati, Assam 781039, India
e-mail: amaresh@iitg.ernet.in

1Corresponding author.

Presented at the 2016 ASME 5th Micro/Nanoscale Heat & Mass Transfer International Conference. Paper No. MNHMT2016-6492.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received June 14, 2016; final manuscript received February 20, 2017; published online March 7, 2017. Assoc. Editor: Zhuomin Zhang.

J. Heat Transfer 139(5), 052002 (Mar 07, 2017) (11 pages) Paper No: HT-16-1380; doi: 10.1115/1.4036036 History: Received June 14, 2016; Revised February 20, 2017

In the present study, the interfacial dynamics of displacement of three-dimensional spherical droplet on a rectangular microchannel wall considering wetting effects are studied. The two-phase lattice Boltzmann Shan−Chen model is used to explore the physics. The main focus of this study is to analyze the effect of wettability, low viscosity ratio, and capillary number on the displacement of spherical droplet subjected to gravitational force on flat as well as grooved surface of the channel wall. The hydrophobic and hydrophilic natures of wettabilities on wall surface are considered to study for viscosity ratio, M1. The results are presented in the form of temporal evolution of wetted length and wetted area for combined viscosity ratios and wettability scenario. In the present study, it is observed that in dynamic droplet displacement, the viscosity ratio and the capillary number play a significant role. It is found that as the viscosity ratio increases, both the wetted area and the wetted length increase and decrease in the case of hydrophilic and hydrophobic wettable walls, respectively. The groove area on the vertical wall tries to entrap fraction of droplet fluid in case of hydrophilic surface of the vertical wall, whereas in hydrophobic case, droplet moves past the groove without entrapment.

Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Gunstensen, A. K. , Rothman, D. H. , Zaleski, S. , and Zanetti, G. , 1991, “ Lattice Boltzmann Model of Immiscible Fluids,” Phys. Rev. A, 43(8), pp. 4320–4327. [CrossRef] [PubMed]
Shan, X. , and Chen, H. , 1993, “ Lattice Boltzmann Model for Simulating Flows With Multiple Phases and Components,” Phys. Rev. E, 47(3), pp. 1815–1819. [CrossRef]
Shan, X. , and Doolen, G. , 1995, “ Multicomponent Lattice-Boltzmann Model With Interparticle Interaction,” J. Stat. Phys., 81(4), pp. 379–393. [CrossRef]
Swift, M. , Osborn, W. , and Yeomans, J. , 1995, “ Lattice Boltzmann Simulation of Nonideal Fluids,” Phys. Rev. Lett., 75(5), pp. 830–833. [CrossRef] [PubMed]
He, X. Y. , Chen, S. Y. , and Zhang, R. Y. , 1999, “ A Lattice Boltzmann Scheme for Incompressible Multiphase Flow and Its Application in Simulation of Rayleigh–Taylor Instability,” J. Comput. Phys., 152(2), pp. 642–663. [CrossRef]
Zhang, J. , 2011, “ Lattice Boltzmann Method for Microfluidics: Models and Applications,” Microfluid. Nanofluid., 10(1), pp. 1–28. [CrossRef]
Fakhari, A. , and Rahimian, M. H. , 2009, “ Simulation of Falling Droplet by the Lattice Boltzmann Method,” Commun. Nonlinear Sci. Numer. Simul., 14(7), pp. 3046–3055. [CrossRef]
Li, Q. , He, Y. L. , Tang, G. H. , and Tao, W. Q. , 2011, “ Lattice Boltzmann Modeling of Microchannel Flows in the Transition Flow Regime,” Microfluid. Nanofluid., 10(3), pp. 607–618. [CrossRef]
Fei, K. , Chen, W. H. , and Hong, C. W. , 2008, “ Microfluidic Analysis of CO2 Bubble Dynamics Using Thermal Lattice-Boltzmann Method,” Microfluid. Nanofluid., 5(1), pp. 119–129. [CrossRef]
Cho, S. C. , Wang, Y. , and Chen, K. S. , 2012, “ Droplet Dynamics in a Polymer Electrolyte Fuel Cell Gas Flow Channel: Forces, Deformation, and Detachment—I: Theoretical and Numerical Analyses,” J. Power Sources, 206, pp. 119–128. [CrossRef]
Cho, S. C. , Wang, Y. , and Chen, K. S. , 2012, “ Droplet Dynamics in a Polymer Electrolyte Fuel Cell Gas Flow Channel: Forces, Deformation and Detachment—II: Comparisons of Analytical Solution With Numerical and Experimental Results,” J. Power Sources, 210, pp. 191–197. [CrossRef]
Hao, L. , and Cheng, P. , 2010, “ Lattice Boltzmann Simulations of Water Transport in Gas Diffusion Layer of a Polymer Electrolyte Membrane Fuel Cell,” J. Power Sources, 195(12), pp. 3870–3881. [CrossRef]
Dimitrakopoulos, P. , and Higdon, J. J. L. , 2001, “ On the Displacement of Three-Dimensional Fluid Droplets Adhering to a Plane Wall in Viscous Pressure-Driven Flows,” J. Fluid Mech., 435, pp. 327–350. [CrossRef]
Schleizer, A. D. , and Bonnecaze, R. T. , 1999, “ Displacement of a Two-Dimensional Immiscible Droplet Adhering to a Wall in Shear and Pressure-Driven Flows,” J. Fluid Mech., 383, pp. 29–54. [CrossRef]
Randive, P. , and Dalal, A. , 2014, “ Influence of Viscosity Ratio and Wettability on Droplet Displacement Behavior: A Mesoscale Analysis,” Comput. Fluids, 102, pp. 15–31. [CrossRef]
Kang, Q. , Zhang, D. , and Chen, S. , 2002, “ Displacement of a Two Dimensional Immiscible Droplet in a Channel,” Phys. Fluids, 14(9), pp. 3203–3214. [CrossRef]
Huang, J. J. , Shu, C. , and Chew, Y. T. , 2009, “ Lattice Boltzmann Study of Droplet Motion Inside a Grooved Channel,” Phys. Fluids, 21(2), p. 022103. [CrossRef]
Son, S. , Chen, L. , Derome, D. , and Carmeliet, J. , 2015, “ Numerical Study of Gravity-Driven Droplet Displacement on a Surface Using the Pseudopotential Multiphase Lattice Boltzmann Model With High Density Ratio,” Comput. Fluids, 117, pp. 42–53. [CrossRef]
Wang, Q. , Li, Y. , Yu, Z. , and Guo, B. , 2016, “ Numerical Simulation of Gravity-Driven Droplet Displacement on an Inclined Micro-Grooved Surface,” ASME Paper No. MNHMT2016-6529.
Kang, Q. , Zhang, D. , and Chen, S. , 2005, “ Displacement of a Three Dimensional Immiscible Droplet in a Channel,” J. Fluid Mech., 545, pp. 41–66. [CrossRef]
Mukherjee, P. P. , Wang, C. Y. , and Kang, Q. , 2009, “ Mesoscopic Modeling of Two-Phase Behavior and Flooding Phenomena in Polymer Electrolyte Fuel Cells,” Electrochim. Acta, 54(27), pp. 6861–6875. [CrossRef]
Martys, N. S. , and Chen, H. , 1996, “ Simulation of Multicomponent Fluids in Complex Three-Dimensional Geometries by the Lattice Boltzmann Method,” Phys. Rev. E, 53(1), pp. 743–750. [CrossRef]
Shan, X. , and Doolen, G. , 1996, “ Diffusion in a Multicomponent Lattice Boltzmann Equation Model,” Phys. Rev. E, 54(4), pp. 3614–3620. [CrossRef]
Dullien, F. A. L. , 1992, Porous Media: Fluid Transport and Pore Structure, Academic Press, San Diego, CA.

Figures

Grahic Jump Location
Fig. 1

(a) Schematic diagram of computational domain and (b) D3Q19 lattice model

Grahic Jump Location
Fig. 6

Effect of viscosity ratio at Ca = 0.35 and g2w = 0.05: (a) time evolution of wetted area and (b) time evolution of wetted length

Grahic Jump Location
Fig. 5

The shape of the droplet in y–z plane at x=40 lu (i.e., (a)–(c)) and x–z plane view at wall (i.e., (d)–(f)) for Ca = 0.35, g2w=0.05, lattice time = 8, and viscosity ratio ((a) M = 0.7, (b) M = 0.8, and (c) M = 0.9)

Grahic Jump Location
Fig. 4

Dynamic droplet behavior under gravity with different lattice times at Ca = 0.35, g2w=0.05, and viscosity ratio ((a) M = 0.7, (b) M = 0.8, and (c) M = 0.9)

Grahic Jump Location
Fig. 3

Variation of contact angle with g2w

Grahic Jump Location
Fig. 2

Static droplet after steady-state

Grahic Jump Location
Fig. 7

The shape of the droplet in y–z plane at x=40 lu (i.e., (a)–(c)) and x–z plane view at wall (i.e., (d)–(f)) for Ca = 0.35, g2w=−0.02, lattice time = 20, and viscosity ratio ((a) M = 0.7, (b) M = 0.8, and (c) M = 0.9)

Grahic Jump Location
Fig. 8

Effect of viscosity ratio at Ca = 0.35 and g2w = −0.02: (a) time evolution of wetted area and (b) time evolution of wetted length

Grahic Jump Location
Fig. 9

The shape of the droplet in x z plane view at wall for g2w=0.05, lattice time = 8, viscosity ratio, M = 0.8, and (a) Ca = 0.1, (b) Ca = 0.35, and (c) Ca = 0.66

Grahic Jump Location
Fig. 10

Schematic of the computational domain of grooved surface vertical wall

Grahic Jump Location
Fig. 11

Dynamic droplet behavior under gravity with different lattice times on grooved wall at Ca = 0.1, g2w=−0.02, viscosity ratio, M = 1, and at different lattice times

Grahic Jump Location
Fig. 12

Dynamic droplet behavior under gravity with different lattice times on grooved wall at Ca = 0.35, g2w=−0.02, viscosity ratio, M = 1, and at different lattice times

Grahic Jump Location
Fig. 15

Dynamic droplet behavior on grooved wall with different lattice times at Ca = 0.35, groove height = 40 lu, g2w=−0.02, and nondimensional time ((a) t = 14.06, (b) t = 17.19, (c) t = 20.31, and (d) t = 23.44)

Grahic Jump Location
Fig. 13

Dynamic droplet behavior under gravity with different lattice times on grooved wall at Ca = 0.66, g2w=−0.02, viscosity ratio, M = 1, and at different lattice times

Grahic Jump Location
Fig. 14

Dynamic droplet behavior on grooved wall with different lattice times at Ca = 0.35, groove height = 20 lu, g2w=−0.02, and nondimensional time ((a) t = 14.06, (b) t = 17.19, (c) t = 20.31, and (d) t = 23.44)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In