Adaptive Lagrangian-Eulerian computation of propagation and rupture of a liquid plug in a tube


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Hassan E. A. , Uzgoren E., Fujioka H., Grotberg J. B. , Shyy W.

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, vol.67, no.11, pp.1373-1392, 2011 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 67 Issue: 11
  • Publication Date: 2011
  • Doi Number: 10.1002/fld.2422
  • Journal Name: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.1373-1392
  • Keywords: ALE, immersed boundary method, multi-phase flows, incompressible flow, mesh adaptation, laminar flow, CARTESIAN GRID METHOD, IMMERSED INTERFACE METHOD, EPITHELIAL-CELL DAMAGE, 2-DIMENSIONAL CHANNEL, STEADY PROPAGATION, MULTIPHASE FLOW, BOUNDARY METHOD, DROP DYNAMICS, FREE-SURFACE, SHARP

Abstract

Liquid plug propagation and rupture occurring in lung airways can have a detrimental effect on epithelial cells. In this study, a numerical simulation of a liquid plug in an infinite tube is conducted using an EulerianLagrangian approach and the continuous interface method. A reconstruction scheme is developed to allow topological changes during plug rupture by altering the connectivity information about the interface mesh. Results prior to the rupture are in reasonable agreement with the study of Fujioka et al. in which a Lagrangian method is used. For unity non-dimensional pressure drop and a Laplace number of 1000, rupture time is shown to be delayed as the initial precursor film thickness increases and rupture is not expected for thicknesses larger than 0.10 of tube radius. During the plug rupture process, a sudden increase of mechanical stresses on the tube wall is recorded, which can cause tissue damage. The peak values of those stresses increase as the initial precursor film thickness is reduced. After rupture, the peaks in mechanical stresses decrease in magnitude as the plug vanishes and the flow approaches a fully developed behavior. Increasing initial pressure drop is shown to linearly increase maximum variations in wall pressure and shear stress. Decreasing the pressure drop and increasing the Laplace number appear to delay rupture because it takes longer for a fluid with large inertial forces to respond to the small pressure drop. Copyright (C) 2010 John Wiley & Sons, Ltd.