Biomedical subjects

Andrew Belmonte

Publications and source records attributed to Andrew Belmonte.

2 recordsLinked to original sources

PubMed2004

Oscillatory rise of bubbles in wormlike micellar fluids with different microstructures.

Previous observations of the nontransient oscillations of rising bubbles and falling spheres in wormlike micellar fluids were limited to a single surfactant system. We present an extensive survey of rising bubbles in another system, an aqueous solution of cetylpyridinium chloride and sodium salicylate, with and without NaCl, across a range of concentrations and temperatures. Two different types of oscillations are seen in different concentration ranges, each with its own temperature dependence. Rheological data identify these different hydrodynamic states with different fluid microstructures.

Journal Article↗

PubMed2003

Oscillations of a solid sphere falling through a wormlike micellar fluid.

We present an experimental study of the motion of a solid sphere falling through a wormlike micellar fluid. While smaller or lighter spheres quickly reach a terminal velocity, larger or heavier spheres are found to oscillate in the direction of their falling motion. The onset of this instability correlates with a critical value of the velocity gradient scale Gamma(c) approximately s(-1). We relate this condition to the known complex rheology of wormlike micellar fluids, and suggest that the unsteady motion of the sphere is caused by the formation and breaking of flow-induced structures.

Journal Article↗