title: Effective rheology of bubbles moving in a capillary tube.
abstract: We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train, considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.
authors.affiliation: Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim, Norway. Santanu.Sinha@ntnu.no
authors.forename: Santanu
authors.initials: S
authors.lastname: Sinha
authors.forename: Alex
authors.initials: A
authors.lastname: Hansen
authors.forename: Dick
authors.initials: D
authors.lastname: Bedeaux
authors.forename: Signe
authors.initials: S
authors.lastname: Kjelstrup
mesh_terms: D002197:Capillary Action; D003198:Computer Simulation; D004058:Diffusion; D005740:Gases / Q000737:chemistry*; D008956:Models, Chemical; D012212:Rheology / Q000379:methods*; D014783:Viscosity
chemical_list: D005740:Gases