Dynamic hysteresis in the rheology of complex fluids

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Journal Title
Journal ISSN
Volume Title
School of Science | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2015
Major/Subject
Mcode
Degree programme
Language
en
Pages
042314/1-8
Series
Physical Review E, Volume 91, Issue 4
Abstract
Recently, rheological hysteresis has been studied systematically in a wide range of complex fluids combining global rheology and time-resolved velocimetry. In this paper we present an analysis of the roles of the three most fundamental mechanisms in simple-yield-stress fluids: structure dynamics, viscoelastic response, and spatial flow heterogeneities, i.e., time-dependent shear bands. Dynamical hysteresis simulations are done analogously to rheological ramp-up and -down experiments on a coupled model which incorporates viscoelasticity and time-dependent structure evolution. Based on experimental data, a coupling between hysteresis measured from the local velocity profiles and that measured from the global flow curve has been suggested. According to the present model, even if transient shear banding appears during the shear ramps, in typical narrow-gap devices, only a small part of the hysteretic response can be attributed to heterogeneous flow. This results in decoupling of the hysteresis measured from the local velocity profiles and the global flow curve, demonstrating that for an arbitrary time-dependent rheological response this proposed coupling can be very weak.
Description
Keywords
complex fluids, rheology, hysteresis
Other note
Citation
Puisto, Antti & Mohtaschemi, Mikael & Alava, Mikko J. & Illa, Xavier. 2015. Dynamic hysteresis in the rheology of complex fluids. Physical Review E. Volume 91, Issue 4. 042314/1-8. ISSN 1539-3755 (printed). DOI: 10.1103/physreve.91.042314.