Floppiness and Flow

Samenvatting

I propose to describe the flow of bubbles, grains, droplets and other disordered athermal media, by developing a new approach for flowing disordered media, building on recent fruitful ideas on the jamming transition in static disordered media. Jamming is the nonequilibrium transition to rigidity that governs the critical scaling of elastic and vibrational properties of disordered systems. These scalings are intimately related to the proximity of floppy motions, complex deformations that, at jamming, can be performed without doing work.

I claim that floppy motions also play an important role when the system is forced to flow under shear. Qualitatively, slow flows of disordered media exhibit anomalous scaling similar to static media, and particle motion organizes in swirls, strikingly similar to the floppy modes of static systems. Thus the goal of this project: to probe the relationship between floppiness and flow.

The project will progress along three lines of attack, using simulations of the bubble model for foams. To begin, I will perform the first normal mode analysis of soft sphere packings with viscous dissipation, probing analogies to static systems where anomalous bulk behavior is encoded in an anomalous excess of low-frequency (soft) modes near jamming. Secondly, I will show that Herschel-Bulkley (power law) rheology, which empirically describes many soft matter systems, emerges naturally as a scaling relation in the jamming context, by probing relations between microscopic interactions and macroscopic scaling laws. Finally, I will develop a novel mapping relating elements of force and contact networks in overdamped flow, and use it to show that notions of floppiness clarify the interplay of elastic and viscous forces. Working at Leiden will permit close collaboration with the excellent nonequilibrium systems and complex fluids groups of Wim van Saarloos (theory) and Martin van Hecke (experiment).

Output

Wetenschappelijk artikel

  • BP Tighe, JH Snoeijer, TJH Vlugt, M van Hecke(2010): "The force network ensemble for granular packings" Soft Matter pp. 2908 - 2917
  • G Katgert, BP Tighe, ME Mobius, M van Hecke(2010): "Couette flow of two-dimensional foams" Europhysics Letters pp. 54002 - n/a
  • BP Tighe, M van Hecke, W van Saarloos, JJC Remmers, E Woldhuis(2010): "Model for the scaling of stresses and fluctuations in flows near jamming" Physical Review Letters pp. 088303
  • BP Tighe, TJH Vlugt(2010): "Force balance in canonical ensembles of static granular packings" Journal of Statistical Mechanics pp. n/a - n/a
  • B.P. Tighe(2011): "Relaxations and rheology near jamming" Physical Review Letters pp. 158303 - n/a
  • B.P. Tighe, T.J.H. Vlugt(2011): "Stress fluctuations in granular force networks" JSTAT pp. n/a - n/a
  • BP Tighe(2012): Dynamic critical scaling in damped random spring networks Physical Review Letters pp. 168303 - 168303
  • M Pica Ciamarra, P Richard, M Schroeter, BP Tighe(2012): Statistical mechanics for static granular media: open questions Soft Matter pp. 9731 - 9731
  • S Dagois-Bohy, BP Tighe, J Simon, S Henkes, M van Hecke(2012): "Soft Sphere Packings at Finite Pressure but Unstable to Shear" Physical Review Letters pp. 095703 - 095703

Kenmerken

Projectnummer

680-47-401

Hoofdaanvrager

Dr. B.P. Tighe

Verbonden aan

Technische Universiteit Delft, Faculteit Werktuigbouwkunde, Maritieme Techniek en Technische Materiaalws. (3ME), Process & Energy

Uitvoerders

Dr. B.P. Tighe

Looptijd

01/01/2010 tot 07/06/2013