Seminar über aktuelle Fragen zur Dynamik komplexer Fluide: Granular matter: friction and chaos

Seminar über aktuelle Fragen zur Dynamik komplexer Fluide

  • Date: Jul 6, 2018
  • Time: 10:15 AM - 11:15 AM (Local Time Germany)
  • Speaker: Dr. Shibu Saw
  • University of Goettingen
  • Location: Max-Planck-Institut für Dynamik und Selbstorganisation (MPIDS)
  • Room: SR 0.77
  • Host: DCF
  • Contact:
The dependence of shear stress on the applied shear rate i.e. flow curve is very different for frictionless and frictional granular particles. The frictionless grains exhibit smooth transition from plastic flow at high shear rates to inertial flow at low shear rates. With the introduction of friction this transition becomes discontinuous. For sufficiently large system, however, the above-mentioned discontinuous transition is absent and instead, the shear stress exhibits a temporal chaotic behaviour in the crossover regime. This chaotic behaviour originates from the presence of a shear stress band with a finite life time. Small systems, in stress-controlled simulations, flow in plastic as well as inertial regimes but depicts jamming in the crossover regime.
The transition from crossover (jammed sate) to inertial regime exhibits hysteresis of shear strain and fractional number of sliding particles both. This hysteresis is, however, absent in the crossover (jammed state) to plastic regime transition. In this talk the nature of shear stress bands at different shear rates and its correlation with different quantities such as contact number distribution will be discussed.
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