Particle transport in a moving corner

• Published in: Journal of fluid mechanics Vol. 559; pp. 379 - 390
• Main Authors: LAINE-PEARSON, F. E., HYDON, P. E.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 25.07.2006
• Subjects: Biological and medical sciences; Biomechanics. Biorheology; Eddies; Fluid mechanics; Fundamental and applied biological sciences. Psychology; Haemodynamics, pneumodynamics; Tissues, organs and organisms biophysics; Pulmonary alveolus; Particle motion; Lung; Pneumodynamics; Modeling; Chaotic systems; Stokes flow
• ISSN: 0022-1120; 1469-7645
• DOI: 10.1017/S0022112006009967

This paper describes particle transport in Stokes flow in a two-dimensional corner whose walls oscillate, which is a simple model for particle transport in the pulmonary alveoli. Formally speaking, the wall motion produces a perturbation to the well-known Moffatt corner eddies. However, this ‘perturbation’ is dominant as the corner is approached. The motion of particles is regular near to the corner. Far from the corner, chaotic motion within the main part of the flow is restricted to very small regions. We deduce that there is competition between the far-field motion that generates eddies and the wall motion. The relative strengths of these two motions determines whether a given particle moves regularly or chaotically. Consequently, there is an intermediate region in which chaotic transport is maximized.