Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-22T02:14:10.388Z Has data issue: false hasContentIssue false

Motion of large bubbles in curved channels

Published online by Cambridge University Press:  14 October 2021

Metin Muradoglu
Affiliation:
Department of Mechanical Engineering, Koc University, Rumelifeneri Yolu, Sariyer 34450 Istanbul, [email protected]
Howard A. Stone
Affiliation:
Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, [email protected]

Abstract

We study the motion of large bubbles in curved channels both semi-analytically using the lubrication approximation and computationally using a finite-volume/front-tracking method. The steady film thickness is governed by the classical Landau–Levich–Derjaguin–Bretherton (LLDB) equation in the low-capillary-number limit but with the boundary conditions modified to account for the channel curvature. The lubrication results show that the film is thinner on the inside of a bend than on the outside of a bend. They also indicate that the bubble velocity relative to the average liquid velocity is always larger in a curved channel than that in a corresponding straight channel and increases monotonically with increasing channel curvature. Numerical computations are performed for two-dimensional cases and the computational results are found to be in a good agreement with the lubrication theory for small capillary numbers and small or moderate channel curvatures. For moderate capillary numbers the numerical results for the film thickness, when rescaled to account for channel curvature as suggested in the lubrication calculation, essentially collapse onto the corresponding results for a bubble in a straight tube. The lubrication theory is also extended to the motion of large bubbles in a curved channel of circular cross-section.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Aussillous, P. & Quere, D. 2000 Quick deposition of a fluid on the wall of a tube. Phys. Fluids 12, 23672371.10.1063/1.1289396CrossRefGoogle Scholar
Bretherton, F. P. 1961 The motion of long bubbles in tubes. J. Fluid Mech. 10, 166188.10.1017/S0022112061000160CrossRefGoogle Scholar
Garstecki, P., Fischbach, M. A. & Whitesides, G. M. 2005 Design for mixing using bubbles in branched microfluidic channels. Appl. Phys. Lett. 86, 244108.10.1063/1.1946902CrossRefGoogle Scholar
Gaver, D. P., Halpern, D., Jensen, O. E. & Grotberg, J. B. 1996 The steady motion of a semi-infinite bubble through a flexible-walled channel. J. Fluid Mech. 319, 2565.10.1017/S0022112096007240CrossRefGoogle Scholar
Guenther, A., Jhunjhunwala, M., Thalmann, M., Schmidt, M. A. & Jensen, K. F. 2005 Micromixing of miscible liquids in segmented gas-liquid flow. Langmuir 21, 15471555.10.1021/la0482406CrossRefGoogle Scholar
Guenther, A., Khan, S. A., Trachsel, F., Thalmann, M. & Jensen, K. F. 2004 Transport and reaction in microscale segmented flow. Lab on a Chip 4, 278286.10.1039/B403982CCrossRefGoogle Scholar
Halpern, D. & Jensen, O. E. 2002 A semi-infinite bubble advancing into a planar tapered channel. Phys. Fluids 14, 431442.CrossRefGoogle Scholar
Howell, P. D. 2003 Surface-tension-driven flow over a moving curved surface. J. Engng Maths 45, 283308.10.1023/A:1022685018867CrossRefGoogle Scholar
Landau, L. & Levich, B. 1942 Dragging of liquid by a plate. Acta Physiochim. USSR 17, 4254.Google Scholar
Mazouchi, A. & Homsy, G. M. 2001 Free surface stokes flow over topography. Phys. Fluids 13, 27512761.10.1063/1.1401812CrossRefGoogle Scholar
Muradoglu, M. & Gokaltun, S. 2004 Implicit multigrid computations of buoyant drops through sinusoidal constrictions. Trans. ASME J. Appl. Mech. 71, 857865.10.1115/1.1795222CrossRefGoogle Scholar
Muradoglu, M. & Kayaalp, A. 2006 An auxiliary grid method for computations of multiphase flows in complex geometries. J. Comput. Phys. 214, 858877.10.1016/j.jcp.2005.10.024CrossRefGoogle Scholar
Muradoglu, M. & Stone, H. A. 2005 Mixing in a drop moving through a serpentine channel: A computational study. Phys. Fluids 17, 073305.CrossRefGoogle Scholar
Quere, D. 1999 Fluid coating on a fiber. Annu. Rev. Fluid Mech. 31, 347384.10.1146/annurev.fluid.31.1.347CrossRefGoogle Scholar
Ratulowski, J. & Chang, H.-C. 1989 Transport of gas bubbles in capillaries. Phys. Fluids A 1, 16421655.10.1063/1.857530CrossRefGoogle Scholar
Reinelt, D. A. 1995 The primary and inverse instabilities of directional viscous fingering. J. Fluid Mech. 285, 303327.CrossRefGoogle Scholar
Reinelt, D. A. & Saffman, P. G. 1985 The penetration of a finger into a viscous fluid in a channel and tube. SIAM J. Sci. Statist. Comput. 6, 542557.10.1137/0906038CrossRefGoogle Scholar
Roy, R. V., Roberts, A. J. & Simpson, M. E. 2002 A lubrication model of coating flows over a curved substrate in space. J. Fluid Mech. 454, 235261.CrossRefGoogle Scholar
Schwartz, L. W. & Weidner, D. E. 1995 Modeling of coating flows on curved surfaces. J. Engng. Maths 29, 91103.10.1007/BF00046385CrossRefGoogle Scholar
Song, H., Bringer, M. R., Tice, J. J., Gerdts, C. J. & Ismagilov, R. F. 2003 Scaling of mixing by chaotic advection in droplets moving through microfluidic channels. Appl. Phys. Lett. 83, 46624666.10.1063/1.1630378CrossRefGoogle ScholarPubMed
Squires, T. M. & Quake, S. R. 2005 Microfluidics: Fluid physics at the nanoliter scale. Rev. Mod. Phys. 77, 9771026.10.1103/RevModPhys.77.977CrossRefGoogle Scholar
Stone, H. A., Stroock, A. D. & Ajdari, A. 2004 Engineering flows in small devices: Microfluidics toward a lab-on-a-chip. Annu. Rev. Fluid Mech. 36, 381411.CrossRefGoogle Scholar
Stone, Z. B. & Stone, H. A. 2005 Imaging and quantifying mixing in a model droplet micromixer. Phys. Fluids 17, 063103.CrossRefGoogle Scholar
Thulasidas, T. C., Abraham, M. A. & Cerro, R. L. 1995 Bubble-train flow in capillaries of circular and square cross section. Chem. Engng Sci. 50, 183199.CrossRefGoogle Scholar
Tryggvason, G., Bunner, B., Esmaeeli, A., Juric, D., Al-Rawahi, N., Tauber, W., Han, J., Nas, S. & Jan, Y.-J. 2001 A front-tracking method for the computations of multiphase flow. J. Comput. Phys. 169, 708759.CrossRefGoogle Scholar
Unverdi, S. & Tryggvason, G. 1992 A front-tracking method for viscous, incompressible multi-fluid flows. J. Comput. Phys. 100, 2537.CrossRefGoogle Scholar
Wong, H., Radke, C. J. & Morris, S. 1995 The motion of long bubbles in polygonal capillaries. Part 1. Thin films. J. Fluid Mech. 292, 7194.10.1017/S0022112095001443CrossRefGoogle Scholar