Pipe flow of a dense emulsion: homogeneous shear-thinning or shear-induced migration ?

Abstract : The flow field of a 70% concentrated noncolloidal o/w emulsion in a pipe has been investigated by means of Particle Image Velocimetry in a matched refractive index medium. At steady state and in laminar regime, the shape of axial velocity profiles is not parabolic and exhibits a shear‐thinning behavior of the dense emulsion, with a flow index of 0.5 and a negligible yield stress (less than 1 Pa). However, instead of a square root law, the pressure drop increases linearly with Um. To explain this apparent inconsistency, two mechanisms of different nature are considered. The first originates from a possible relation between the consistency factor and the drop mean diameter. The second mechanism is shear‐induced migration and leads to the development of a concentration gradient in the pipe cross section. Both mechanisms considered reconcile the experimental data, the apparent local shear‐thinning behavior and the linear evolution of the pressure drop with the flow rate.
Complete list of metadatas

Cited literature [36 references]  Display  Hide  Download

https://hal-ifp.archives-ouvertes.fr/hal-01702338
Contributor : Françoise Bertrand <>
Submitted on : Monday, May 20, 2019 - 5:47:23 PM
Last modification on : Monday, July 15, 2019 - 2:20:05 PM

File

Abbas_20374.pdf
Files produced by the author(s)

Identifiers

Citation

Micheline Abbas, Amélie Pouplin, Olivier Masbernat, Alain Line, Sandrine Decarre. Pipe flow of a dense emulsion: homogeneous shear-thinning or shear-induced migration ?. AIChE Journal, Wiley, 2017, 63 (11), pp.5182-5195. ⟨10.1002/aic.15811⟩. ⟨hal-01702338⟩

Share

Metrics

Record views

127

Files downloads

30