Our group is investigating rheology, biorheology, ultrasonics and suspension mechanics.
Suspension dynamics is being studied by using magnetic resonance (NMR) imaging. Current work focuses on the development of an NMR imaging viscometer and the use of NMR imaging to measure flows of opaque suspensions, such as paper pulp suspensions.
Macroscopic rheological properties of suspensions of spherical and rodlike particles are being investigated. Suspensions of multisized spherical particles are examined theoretically and experimentally. Using facing ball rheometry to determine the viscosity of suspensions of rodlike particles, we have been able to elucidate the effect of particle volume fraction, aspect ratio, and microstructure. Rheological studies conducted with pulp suspensions are facilitating the design of new unit operations for the paper industry.
Biorheological studies are being carried out to elucidate the mechanical interactions between spermatozoa and their environment. Long-range goals of this work include finding a synthetic medium which can be used for clinical tests and quantitatively determining the role of mucus properties on fertility.
Experimental and theoretical investigations have shown that low concentrations of a polymer additive in water can dramatically alter nonlinear wave propagation in viscoelastic fluids. This work is being extended to a wider range of non-Newtonian fluids as well as to suspensions and other fluids with microstructure.