Hostname: page-component-76fb5796d-2lccl Total loading time: 0 Render date: 2024-04-29T05:53:31.029Z Has data issue: false hasContentIssue false

The pulsatile propagation of a finger of air within a fluid-occluded cylindrical tube

Published online by Cambridge University Press:  25 April 2008

BRADFORD J. SMITH
Affiliation:
Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USAdonald.gaver@tulane.edu
DONALD P. GAVER III
Affiliation:
Department of Biomedical Engineering, Tulane University, New Orleans, LA 70118, USAdonald.gaver@tulane.edu

Abstract

We computationally investigate the unsteady pulsatile propagation of a finger of air through a liquid-filled cylindrical rigid tube. The flow field is governed by the unsteady capillary number CaQ(t)=μQ*(t*)/πR2γ, where R is the tube radius, Q* is the dimensional flow rate, t* is the dimensional time, μ is the viscosity, and γ is the surface tension. Pulsatility is imposed by CaQ(t) consisting of both mean (CaM) and oscillatory (CaΩ components such that CaQ(t)=CaM+CaΩ sin(Ωt). Dimensionless frequency and amplitude parameters are defined, respectively, as Ω=μωR/γ and A=2CaΩ/Ω, with Ω epresenting the frequency of oscillation. The system is accurately described by steady-state behaviour if CaΩ<CaM; however, when CaΩ>CaM, reverse flow exists during a portion of the cycle, leading to an unsteady regime. In this unsteady regime, converging and diverging surface stagnation points translate dynamically along the interface throughout the cycle and may temporarily separate to create internal stagnation points at high Ω. For CaΩ<10CaM, the bubble tip pressure drop ΔPtip may be estimated accurately from the pressure measured downstream of the bubble tip when corrections for the downstream viscous component of the pressure drop are applied. The normal stress gradient at the tube wall ∂τn/∂z is examined in detail, because this has been shown to be the primary factor responsible for mechanical damage to epithelial cells during pulmonary airway reopening (Bilek, Dee & Gaver III 2003; Kay et al. 2004). In the unsteady regime, local film-thinning produces high ∂τn/∂z at low CaΩ; however, film thickening at moderate Ca protects the tube wall from large ∂τn/∂z. This stress field is highly dynamic and exhibits intriguing spatial and temporal characteristics that may be used to reduce ventilator-induced lung injury.

Type
Papers
Copyright
Copyright © Cambridge University Press 2008

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

Becker, A. A. 1992 The Boundary Element Method in Engineering: A Complete Course. McGraw-Hill.Google Scholar
Bilek, A. M., Dee, K. C. & Gaver, D. P. III 2003 Mechanisms of surface-tension-induced epithelial cell damage in a model of pulmonary airway reopening. J. Appl. Physiol. 94, 770783.CrossRefGoogle Scholar
Bretherton, F. P. 1961 The motion of long bubbles in tubes. J. Fluid Mech. 10, 166188.CrossRefGoogle Scholar
Cox, B. G. 1962 On driving viscous fluid out of a tube. J. Fluid Mech. 14, 8196.CrossRefGoogle Scholar
Fairbrother, F. & Stubbs, A. E. 1935 Studies in electroendosmosis. Part VI. The bubble-tube method of measurements. J. Chem. Soc. 1, 527529.CrossRefGoogle Scholar
Fujioka, H. & Grotberg, J. B. 2004 Steady propagation of a liquid plug in a 2d-channel. Trans. ASME K: J. Biomech. Engng 126, 567577.Google Scholar
Fujioka, H. & Grotberg, J. B. 2005 Steady propagation of a surfactant laden liquid plug in a 2d-channel. Phys. Fluids 17, 082102.CrossRefGoogle Scholar
Gaver III, D. P, Samsel, R. W. & Solway, J. 1990 Effects of surface tension and viscosity on airway reopening. J. Appl. Physiol. 69, 7485.CrossRefGoogle Scholar
Gaver, D. P III, 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.CrossRefGoogle Scholar
Gaver, D. P. III, Jacob, A.-M., Bilek, A. M. & Dee, K. C. 2006 The significance of air-liquid interfacial stresses on low-volume ventilator-induced lung injury. In Ventilator-Induced Lung Injury (ed. Dreyfuss, D., Saumon, G. & Hubmayr, R. D.), pp. 157205. Taylor and Francis.Google Scholar
Ghadiali, S. N. & Gaver, D. P. III 2003 The influence of non-equilibrium surfactant dynamics on the flow of a semi-infinite bubble in a rigid cylindrical capillary tube. J. Fluid Mech. 478, 165196.CrossRefGoogle Scholar
Ghadiali, S. N., Halpern, D. & Gaver, D. P. III 2001 A dual-reciprocity boundary element method for evaluating bulk convective transport of surfactant in free-surface flows. J. Comput. Phys. 171 534559.CrossRefGoogle Scholar
Giavedoni, M. D. & Saitia, F. A. 1997 The axisymmetric and plane cases of a gas phase steadily displacing a Newtonian fluid – a simultaneous solution of governing equations. Phys. Fluids 9, 24202428.CrossRefGoogle Scholar
Grotberg, J. B. 2001 Respiratory fluid mechanics and transport processes. Annu. Rev. Biomed. Engng. 3, 421457.CrossRefGoogle ScholarPubMed
Halpern, D. & Gaver, D. P. III 1994 Boundary element analysis of the time-dependent motion of a semi-infinite bubble in a channel. J. Comput. Phys. 115, 366375.CrossRefGoogle Scholar
Hazel, A. L. & Heil, M. 2003 Three-dimensional airway reopening: the steady propagation of a semi-infinite bubble into a buckled elastic tube. J. Fluid Mech. 478, 4770.CrossRefGoogle Scholar
Hazel, A. L. & Heil, M. 2006 Finite-Reynolds-number effects in steady, three-dimensional airway reopening. Trans. ASME K: J. Biomed. Engng 128, 573578.Google ScholarPubMed
Heil, M. 2000 Finite Reynolds number effects in the propagation of an air finger into a liquid-filled flexible-walled channel. J. Fluid Mech. 424, 2144.CrossRefGoogle Scholar
Heil, M. 2001 Finite Reynolds number effects in the bretherton problem. Phys. Fluids 13, 25172521.CrossRefGoogle Scholar
Ingham, D. B., Ritchie, J. A. & Taylor, C. M. 1992 The motion of a semi-infinite bubble between parallel plates. Z. Angew. Math. Phys. 43, 191206.CrossRefGoogle Scholar
Juel, A. & Heap, A. 2006 The reopening of a collapsed fluid-filled elastic tube. J. Fluid Mech. 572, 287310.CrossRefGoogle Scholar
Kay, S. S., Bilek, A. M., Dee, K. C. & Gaver, D. P. III 2004 Pressure gradient, not exposure duration, determines the extent of epithelial cell damage in a model of pulmonary airway reopening. J. Appl. Physiol. 97, 269276.CrossRefGoogle ScholarPubMed
Ladyzhenskaya, O. A. 1963 The Mathmatical Theory of Viscous Incompressible Flow. Gordon and Breach.Google Scholar
Lu, W.-Q. & Chang, H.-C. 1988 An extension of the biharmonic boundary integral method to free surface flow in channels. J. Comput. Phys. 77, 340360.CrossRefGoogle Scholar
Park, C. M. & Homsy, G. W. 1984 Two-phase displacement in hele-shaw cells: theory. J. Fluid Mech. 139, 291308.CrossRefGoogle Scholar
Perun, M. L. & Gaver, D. P. III 1995 a An experimental model investigation of the opening of a collapsed untethered pulmonary airway. Trans. ASME K: J. Biomech. Engng 117, 245253.Google ScholarPubMed
Perun, M. L. & Gaver, D. P. III 1995 b The interaction between airway lining fluid forces and parenchymal tethering during pulmonary airway reopening. J. Appl. Physiol. 75, 17171728.CrossRefGoogle Scholar
Rame, E. 2007 The stagnation point in marangoni-thickened landau-levich type flows. Phys. Fluids 19, 078102.CrossRefGoogle Scholar
Ratulowski, J. & Chang, H.-C. 1989 Transport of gas bubbles in capillaries. Phys. Fluids A 1, 16421655.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. Stat. Comput. 6, 542.CrossRefGoogle Scholar
Shen, E. I. & Udell, K. S. 1985 A finite element study of low reynolds number two-phase flow in cylindrical tubes. Trans. ASME E: ASME J. Appl. Mech. 52, 253256.CrossRefGoogle Scholar
Stebe, K. J. & Barthes-Biesel, D. 1995 Marangoni effects of adsorption –desorption controlled surfactants on the leading edge of an infinitely long bubble in a capillary. J. Fluid Mech 286, 2548.CrossRefGoogle Scholar
Stebe, K. J. & Maldarelli, C. 1994 Remobilizing surfactant retarded fluid particle interfaces ii. controlling the surface mobility at interfaces of solutions containing surface active components. J. Colloid Interface Sci. 163, 177189.CrossRefGoogle Scholar
Wassmuth, F., Laidlaw, W. G. & Coombe, D. A. 1993 Calculation of Interfacial flows and surfactant redistribution as a gas/liquid interface moves between two parallel plates. Phys. Fluids A 5, 15331548.CrossRefGoogle Scholar
Yap, D. Y. K. & Gaver, D. P. III 1998 The influence of surfactant on two-phase flow in a flexible-walled channel under bulk equilibrium conditions. Phys. Fluids 10, 18461863.CrossRefGoogle Scholar
Yap, D. Y. K., Liebkemann, W. D., Solway, J. & Gaver, D. P. III. 1994 The influence of parenchymal tethering on the reopening of closed pulmonary airways. J. Appl. Physiol. 76, 20952105.CrossRefGoogle ScholarPubMed
Zimmer, M. E., Williams, H. A. R. & Gaver, D. P. III 2005 The pulsatile motion of a semi-infinite bubble in a channel: flow fields, and transport of an inactive surface-associated contaminant. J. Fluid Mech. 537, 133.CrossRefGoogle Scholar