Viscoelastic instability of Poiseuille flow

• Applicant: Professor Dr. Christian Wagner
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Experimental Condensed Matter Physics
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 157269621

• Final Report Year: 2018

Final Report Abstract

In summary, we have characterised the bifurcation scenario of the primary threshold of the viscoelastic instability in a curvilinear channel. We could show that the instability sets in at decreasing critical Weissenberg number Wic along the channel. Closer to the entry of the channel we observed an imperfect bifurcation and only at later positions a simple forward bifurcation. We found a pronounced oscillatory behaviour that has been predicted numerically before. Thus, we thus classify the transition as a Hopf bifurcation, and only with increasing driving strength the oscillation amplitudes and frequencies become time dependent until a featureless state of viscoelstic turbulence is reached.

Publications

• Elasto-inertial turbulence. PNAS 110, 10557 (2013)
  D. Samanta, Y. Dubief, M. Holzner, C. Schaefer, A. Morozov, C. Wagner, and B. Hof
  (See online at https://doi.org/10.1073/pnas.1219666110)