|
Résumé |
Since its discovery in wormlike micelles solutions two decades ago, shear-banding has been documented in most categories of complex fluids until very recently. Beyond the existence of a phase separation, experiments have revealed the ubiquitous presence of flow instabilities. We characterize such instabilities developing in the straight microchannel flow of a wormilke micelles solution by particle image velocimetry. The quantitative agreement with the predictions of a phenomenological tensorial model indicates a new instability mecanism in complex fluids, specific to the presence of shear bands and differing from the now well-established bulk driven viscoelastic ones predicted and observed in curved geometries. |
