Based on numerical simulations of a lattice kinetic model for soft-glassy materials, we characterize the global rheology of a dense emulsion-like system, under three representative load conditions: Couette flow, time-oscillating Strain and Kolmogorov flow. It is found that in all cases the rheology is described by a Herschel-Bulkley (HB) relation, $sigma = {sigma}_{Y} + A S^{eta}$ , with the yield stress ${sigma}_{Y}$ largely independent of the loading scenario. A proper rescaling of the HB parameters permits to describe heterogeneous flows with space-dependent stresses, based on the notion of cooperativity, as recently proposed to characterize the degree of non-locality of stress relaxation phenomena in soft-glassy materials.
Benzi, R., Bernaschi, M., Sbragaglia, M., Succi, S. (2013). Rheological properties of soft-glassy flows from hydro-kinetic simulations. EUROPHYSICS LETTERS, 104(4) [10.1209/0295-5075/104/48006].
Rheological properties of soft-glassy flows from hydro-kinetic simulations
BENZI, ROBERTO;SBRAGAGLIA, MAURO;
2013-01-01
Abstract
Based on numerical simulations of a lattice kinetic model for soft-glassy materials, we characterize the global rheology of a dense emulsion-like system, under three representative load conditions: Couette flow, time-oscillating Strain and Kolmogorov flow. It is found that in all cases the rheology is described by a Herschel-Bulkley (HB) relation, $sigma = {sigma}_{Y} + A S^{eta}$ , with the yield stress ${sigma}_{Y}$ largely independent of the loading scenario. A proper rescaling of the HB parameters permits to describe heterogeneous flows with space-dependent stresses, based on the notion of cooperativity, as recently proposed to characterize the degree of non-locality of stress relaxation phenomena in soft-glassy materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
