Publication details for Prof. Ed LlewellinTruby, J.M., Mueller, S.P., Llewellin, E.W. & Mader, H.M. (2015). The rheology of three-phase suspensions at low bubble capillary number. Proceedings of the Royal Society A 471(2173): 20140557.
- Publication type: Journal Article
- ISSN/ISBN: 1364-5021, 1471-2946
- DOI: 10.1098/rspa.2014.0557
- Further publication details on publisher web site
- Durham Research Online (DRO) - may include full text
Author(s) from Durham
We develop a model for the rheology of a three-phase suspension of bubbles and particles in a Newtonian liquid undergoing steady flow. We adopt an ‘effective-medium’ approach in which the bubbly liquid is treated as a continuous medium which suspends the particles. The resulting three-phase model combines separate two-phase models for bubble suspension rheology and particle suspension rheology, which are taken from the literature. The model is validated against new experimental data for three-phase suspensions of bubbles and spherical particles, collected in the low bubble capillary number regime. Good agreement is found across the experimental range of particle volume fraction (0≤ϕp≲0.5) and bubble volume fraction (0≤ϕb≲0.3). Consistent with model predictions, experimental results demonstrate that adding bubbles to a dilute particle suspension at low capillarity increases its viscosity, while adding bubbles to a concentrated particle suspension decreases its viscosity. The model accounts for particle anisometry and is easily extended to account for variable capillarity, but has not been experimentally validated for these cases.