Skip to main content
SpringerLink
Log in

Numerical simulation of emergence of a water droplet from a pore into a microchannel gas stream

  • Research Paper
  • Published:
Microfluidics and Nanofluidics Aims and scope Submit manuscript

Abstract

A numerical investigation on the dynamic behavior of liquid water entering a microchannel through a lateral opening (pore) in the wall is reported in this paper. The channel dimensions, flow conditions and transport properties are chosen to simulate those in the gas channel of a typical proton exchange membrane fuel cell (PEMFC). Two-dimensional transient simulations employing the volume of fluid method are used to explicitly track the liquid–gas interface, and to gain understanding into the dynamics of a water droplet subjected to airflow in the bulk of the microchannel. A series of parametric studies, including the effects of static contact angle, dimensions of the pore, air-inlet velocity, and water-inlet velocity are performed with a particular focus on the effect of hydrophobicity. The simulations show that the wettability of the microchannel surface has a major impact on the dynamics of the water droplet. Flow patterns are presented and analyzed showing the splitting of a droplet for a hydrophobic surface, and the tendency for spreading and film flow formation for a hydrophilic surface. The time evolution of the advancing and receding contact angles of the droplet are found to be sensitive to the wettability when the gas diffusion layer surface is hydrophilic, but independent of wettability when the surface is hydrophobic. The critical air velocity at which a droplet detaches is found to decrease with increasing hydrophobicity and with increasing initial dimension of the droplet. The critical air velocity found in the present study by taking into account the water transport and evolution of the droplet from a pore are found to differ significantly from previous works which consider a stagnant droplet sitting on the surface.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18

Similar content being viewed by others

References

  • Baschuk JJ, Li X (2000) Modelling of polymer electrolyte membrane fuel cells with variable degrees of water flooding. J Power Sources 86(1–2):181–196

    Article  Google Scholar 

  • Bazylak A, Sinton D, Liu Z-S, Djilali N (2006) Effect of compression on liquid water transport and microstructure of PEMFC gas diffusion layers. J Power Sources 163(2):784–792

    Article  Google Scholar 

  • Berning T, Djilali N (2003) A 3D, multiphase, multicomponent model of the cathode and anode of a PEM fuel cell. J Electrochem Soc 150(12):A1589–A1598

    Article  Google Scholar 

  • Brackbill JU, Kothe DB, Zemach C (1992) A continuum method for modeling surface tension. J Comput Phys 100(2):335–354

    Article  MathSciNet  MATH  Google Scholar 

  • Chen KS, Hickner MA, Noble DR (2005) Simplified models for predicting the onset of liquid water droplet instability at the gas diffusion layer/gas flow channel interface. Int J Energy Res 29(12):1113–1132

    Article  Google Scholar 

  • Dorrer C, Ruhe J (2006) Advancing and receding motion of droplets on ultrahydrophobic post surfaces. Langmuir 22(18):7652–7657

    Article  Google Scholar 

  • Dyer CK (2002) Fuel cells for portable applications. J Power Sources 106(1–2):31–34

    Article  Google Scholar 

  • Extrand CW (2002) Model for contact angles and hysteresis on rough and ultraphobic surfaces. Langmuir 18(21):7991–7999

    Article  Google Scholar 

  • Feindel KW, LaRocque LPA, Starke D, Bergens SH, Wasylishen RE (2004) In situ observations of water production and distribution in an operating H-2/O-2 PEM fuel cell assembly using H-1 NMR microscopy. J Am Chem Soc 126(37):11436–11437

    Article  Google Scholar 

  • Fimrite J, Struchtrup H, Djilali N (2005) Transport phenomena in polymer electrolyte membranes-I. Modeling framework. J Electrochem Soc 152(9):A1804–A1814

    Article  Google Scholar 

  • Gao L, McCarthy TJ (2006) Contact angle hysteresis explained. Langmuir 22(14):6234–6237

    Article  Google Scholar 

  • Hakenjos A, Muenter H, Wittstadt U, Hebling C (2004) A PEM fuel cell for combined measurement of current and temperature distribution, and flow field flooding. J Power Sources 131(1–2):213–216

    Article  Google Scholar 

  • Hickner MA, Siegel NP, Chen KS, McBrayer DN, Hussey DS, Jacobson DL, Arif M (2006) Real-time imaging of liquid water in an operating proton exchange membrane fuel cell. J Electrochem Soc 153(5):A902–A908

    Article  Google Scholar 

  • Hirt CW, Nichols BD (1981) Volume of fluid (VOF) method for the dynamics of free boundaries. J Comput Phys 39(1):201–225

    Article  MATH  Google Scholar 

  • Hu MR, Gu AZ, Wang MH, Zhu XJ, Yu LJ (2004) Three dimensional, two phase flow mathematical model for PEM fuel cell: Part I. Model development. Energy Convers Manage 45(11–12):1861–1882

    Article  Google Scholar 

  • Jiao K, Zhou B, Quan P (2006) Liquid water transport in straight micro-parallel-channels with manifolds for PEM fuel cell cathode. J Power Sources 157(1):226–243

    Article  Google Scholar 

  • Kramer D, Zhang J B, Shimoi R, Lehmann E, Wokaun A, Shinohara K, Scherer G G (2005) In situ diagnostic of two-phase flow phenomena in polymer electrolyte fuel cells by neutron imaging Part A. Experimental, data treatment, and quantification. Electrochim Acta 50(13):2603–2614

    Article  Google Scholar 

  • Kumbur EC, Sharp KV, Mench MM (2006) Liquid droplet behavior and instability in a polymer electrolyte fuel cell flow channel. J Power Sources 161(1):333–345

    Article  Google Scholar 

  • Litster S, Sinton D, Djilali N (2006) Ex situ visualization of liquid water transport in PEM fuel cell gas diffusion layers. J Power Sources 154(1):95–105

    Article  Google Scholar 

  • Mench MM, Wang CY, Ishikawa M (2003) In situ current distribution measurements in polymer electrolyte fuel cells. J Electrochem Soc 150(8):A1052–A1059

    Article  Google Scholar 

  • Pasaogullari U, Wang CY (2004) Liquid water transport in gas diffusion layer of polymer electrolyte fuel cells. J Electrochem Soc 151(3):A399–A406

    Article  Google Scholar 

  • Pekula N, Heller K, Chuang PA, Turhan A, Mench MM, Brenizer JS, Unlu K (2005) Study of water distribution and transport in a polymer electrolyte fuel cell using neutron imaging. Nucl Instrum Methods Phys Res A 542(1–3):134–141

    Article  Google Scholar 

  • Quan P, Zhou B, Sobiesiak A, Liu ZS (2005) Water behavior in serpentine micro-channel for proton exchange membrane fuel cell cathode. J Power Sources 152(1):131–145

    Article  Google Scholar 

  • Satija R, Jacobson DL, Arif M, Werner SA (2004) In situ neutron imaging technique for evaluation of water management systems in operating PEM fuel cells. J Power Sources 129(2):238–245

    Article  Google Scholar 

  • Siegel NP, Ellis MW, Nelson DJ, von Spakovsky MR (2004) A two-dimensional computational model of a PEMFC with liquid water transport. J Power Sources 128(2):173–184

    Article  Google Scholar 

  • Springer TE, Zawodzinski TA, Gottesfeld S (1991) Polymer electrolyte fuel-cell model. J Electrochem Soc 138(8):2334–2342

    Article  Google Scholar 

  • Sugiura K, Nakata M, Yodo T, Nishiguchi Y, Yamauchi M, Itoh Y (2005) Evaluation of a cathode gas channel with a water absorption layer/waste channel in a PEFC by using visualization technique. J Power Sources 145(2):526–533

    Article  Google Scholar 

  • Sui PC, Djilali N (2005) Analysis of water transport in proton exchange membranes using a phenomenological model. ASME J Fuel Cell Sci Technol 2:149–155

    Article  Google Scholar 

  • Theodorakakos A, Ous T, Gavaises A, Nouri JM, Nikolopoulos N, Yanagihara H (2006) Dynamics of water droplets detached from porous surfaces of relevance to PEM fuel cells. J Colloid Interface Sci 300(2):673–687

    Article  Google Scholar 

  • Trabold TA (2005) Minichannels in polymer electrolyte membrane fuel cells. Heat Transf Eng 26(3):3–12

    Article  Google Scholar 

  • Triplett KA, Ghiaasiaan SM, Abdel-Khalik SI, Sadowski DL (1999) Gas-liquid two-phase flow in microchannels - Part I: two-phase flow patterns. Int J Multiphase Flow 25(3):377–394

    Article  MATH  Google Scholar 

  • Tsushima S, Teranishi K, Hirai S (2004) Magnetic resonance imaging of the water distribution within a polymer electrolyte membrane in fuel cells. Electrochem Solid State Lett 7(9):A269–A272

    Article  Google Scholar 

  • Tüber K, Pocza D, Hebling C (2003) Visualization of water buildup in the cathode of a transparent PEM fuel cell. J Power Sources 124(2):403–414

    Article  Google Scholar 

  • Wang ZH, Wang CY, Chen KS (2001) Two-phase flow and transport in the air cathode of proton exchange membrane fuel cells. J Power Sources 94(1):40–50

    Article  Google Scholar 

  • Weng FB, Su A, Hsu CY, Lee CY (2006) Study of water-flooding behaviour in cathode channel of a transparent proton-exchange membrane fuel cell. J Power Sources 157(2):674–680

    Article  Google Scholar 

  • Yang XG, Zhang FY, Lubawy AL, Wang CY (2004) Visualization of liquid water transport in a PEFC. Electrochem Solid State Lett 7(11):A408–A411

    Article  Google Scholar 

  • Youngs DL (1982) Time-dependent multi-material flow with large fluid distortion. In: Morton KW, Bianes MJ (eds) Numerical methods for fluid dynamics. Academic, New York, pp 273–285

    Google Scholar 

  • You LX, Liu HT (2002) A two-phase flow and transport model for the cathode of PEM fuel cells. Int J Heat Mass Transf 45(11):2277–2287

    Article  MATH  Google Scholar 

  • Zhang FY, Yang XG, Wang CY (2006) Liquid water removal from a polymer electrolyte fuel cell. J Electrochem Soc 153(2):A225–A232

    Article  Google Scholar 

  • FLUENT 6.2 User’s Guide, FLUENT. 2006

Download references

Acknowledgments

XZ is grateful for the support of the National Natural and Science Foundation of China (No. 90410005), the Excellent Young Teachers Program of M0E, P. R. C. ([2003]355#), Applied Foundation Research of Chongqing (No. 2003–7966), and the China Scholarship programs. ND and PCS acknowledge the financial support of the MITACS Network of Centres of Excellence, Ballard Power Systems and the Canada Research Chairs program.

Author information

Authors and Affiliations

  1. Institute of Engineering Thermophysics, Chongqing University, Chongqing, 400044, China

    Xun Zhu

  2. Institute for Integrated Energy Systems and Department of Mechanical Engineering, University of Victoria, Victoria, BC, V8W 3P6, Canada

    P. C. Sui & Ned Djilali

Authors
  1. Xun Zhu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. P. C. Sui
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ned Djilali
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Ned Djilali.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Zhu, X., Sui, P.C. & Djilali, N. Numerical simulation of emergence of a water droplet from a pore into a microchannel gas stream. Microfluid Nanofluid 4, 543–555 (2008). https://doi.org/10.1007/s10404-007-0209-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10404-007-0209-9

Keywords

Search

Navigation