Effects of Surface Tension and Yield Stress on Mucus Plug Rupture: a Numerical Study
Article dans une revue avec comité de lecture
JournalJournal of Biomechanical Engineering
We study the effects of surface tension and yield stress on mucus plug rupture. A three-dimensional simplified configuration is employed to simulate mucus plug rupture in a collapsed lung airway of the 10 th generation. The Herschel-Bulkley model is used to take into account the non-Newtonian viscoplastic fluid properties of mucus. Results show that the maximum wall shear stress greatly changes right prior to the rupture of the mucus plug. The surface tension influences mainly the late stage of the rupture process when the plug deforms greatly and the curvature of the mucus-air interface becomes significant. High surface tension increases the wall shear stress and the time needed to rupture since it produces a resistance to the rupture, as well as strong stress and velocity gradients across the mucus-air interface. The yield stress effects are pronounced mainly at the beginning. High yield stress makes the plug take long time to yield and slows down the whole rupture process. When the effects induced by the surface tension and yield forces are comparable, dynamical quantities strongly depend on the ratio of the two forces. The pressure difference (the only driving in the study) contributes to wall shear stress much more than yield stress and surface tension per unit length. Wall shear stress is less sensitive to the variation in yield stress than that in surface tension. In general, wall shear stress can be effectively reduced by the smaller pressure difference and surface tension.
Files in this item
Showing items related by title, author, creator and subject.
Article dans une revue avec comité de lectureROMANÒ, Francesco; FUJIOKA, H.; MURADOGLU, M.; GROTBERG, J. B. (American Physical Society, 2019)The closure of a human lung airway is modeled as an instability of a two-phase flow in a pipe coated internally with a Newtonian liquid. For a thick enough coating, the Plateau-Rayleigh instability creates a liquid plug ...
Article dans une revue avec comité de lectureBARETTER, Alberto; GODARD, Benjamin; JOSEPH, Pierric; ROUSSETTE, Olivier; ROMANÒ, Francesco; BARRIER, Raphael; DAZIN, Antoine (MDPI AG, 2021)On many occasions, fan or compressor stages have to face azimuthal flow distortion at inlet, which affects their performance and stability. These flow distortions can be caused by external events or by some particular ...
Communication avec acteBARETTER, Alberto; JOSEPH, Pierric; ROUSSETTE, Olivier; ROMANO, Francesco; DAZIN, Antoine (ASME, 2022-06)In aircraft engines, compressor stages can encounter situations in which the flow is distorted at rotor inlet, for example during particular flight maneuvers, or due to the shape of the inlet of the airframe. The main ...
Article dans une revue avec comité de lectureROMANÒ, Francesco (American Physical Society, 2019)All the methods which estimate the unperturbed fluid flow velocity relying on particle suspensions address the same question: How can the fluid velocity be computed measuring the particles trajectory and/or their velocities? ...
The ACONIT project: an innovative design approach of active flow control for surge prevention in gas turbines Communication avec acteDAZIN, A; JOSEPH, P; ROMANO, F; GALLAS, Q; MARTY, J; AIGOUY, G; STÔΒEL, M; NIEHUIS, R (IOP Publishing, 2021-01-22)The objective of the ACONIT project is to design, manufacture and test actuators for flow control for an implantation in an aircraft engine. The actuators will fulfil aeronautics requirement in order to increase the ...