Tollmien-Schlichting route to elastoinertial turbulence in channel flow

@article{Shekar2021TollmienSchlichtingRT,
  title={Tollmien-Schlichting route to elastoinertial turbulence in channel flow},
  author={Ashwin Shekar and Ryan Michael McMullen and Beverley J. McKeon and Michael D. Graham},
  journal={Physical Review Fluids},
  year={2021}
}
Direct simulations of two-dimensional channel flow of a viscoelastic fluid have revealed the existence of a family of Tollmien-Schlichting (TS) attractors that is nonlinearly self-sustained by viscoelasticity [Shekar et al., J. Fluid Mech. 893, A3 (2020)]. Here, we describe the evolution of this branch in parameter space and its connections to the Newtonian TS attractor and to elastoinertial turbulence (EIT). At Reynolds number Re = 3000, there is a solution branch with TS-wave structure but… Expand
Understanding viscoelastic flow instabilities using the Oldroyd-B model
The Oldroyd-B model has been used extensively to predict a host of instabilities in shearing flows of viscoelastic fluids, polymer solutions in particular. The present review, written on the occasionExpand
Perspectives on viscoelastic flow instabilities and elastic turbulence
Viscoelastic fluids are a common subclass of rheologically complex materials that are encountered in diverse fields from biology to polymer processing. Often the flows of viscoelastic fluids areExpand
Subcritical and supercritical bifurcations in axisymmetric viscoelastic pipe flows
  • Dongdong Wan, Guangrui Sun, Mengqi Zhang
  • Physics
  • Journal of Fluid Mechanics
  • 2021
Abstract Axisymmetric viscoelastic pipe flow of Oldroyd-B fluids has been recently found to be linearly unstable by Garg et al. (Phys. Rev. Lett., vol. 121, 2018, 024502). From a nonlinear point ofExpand

References

SHOWING 1-10 OF 71 REFERENCES
Beyond the maximum drag reduction asymptote: the pseudo-laminar state
Recent experiments indicated that polymers can reduce the turbulent drag beyond the asymptotic limit known as the MDR, leading to a laminar flow. In this Letter, we show through direct numericalExpand
Exceeding the Asymptotic Limit of Polymer Drag Reduction.
TLDR
It is shown that, for an appropriate choice of parameters, polymers can reduce the drag beyond the suggested asymptotic limit, eliminating turbulence and giving way to laminar flow. Expand
THREE-DIMENSIONAL COHERENT STATES IN PLANE SHEAR FLOWS
Three-dimensional steady states in plane Couette flow and traveling-wave solutions in plane Poiseuille flow are calculated for stress boundary conditions. The procedure is tied to a self-sustainingExpand
Critical-Layer Structures and Mechanisms in Elastoinertial Turbulence.
TLDR
Computations of self-sustained nonlinear Tollmien-Schlichting waves reveal that the critical layer exhibits stagnation points that generate sheets of large polymer stretch, which may be the genesis of similar structures in EIT. Expand
Nonlinear travelling waves as a framework for understanding turbulent drag reduction
Nonlinear travelling waves that are precursors to laminar–turbulent transition and capture the main structures of the turbulent buffer layer have recently been found to exist in all the canonicalExpand
  • Structures and mechanisms in elastoinertial turbulence
  • 2021
Degeneracy of turbulent states in two-dimensional channel flow
Abstract We revisit two-dimensional channel flow with fixed volume flux for Reynolds numbers $Re\in [7000,72\,000]$ via direct numerical simulations and uncover a region of multistability ofExpand
Energy growth in subcritical viscoelastic pipe flows
  • Mengqi Zhang
  • Physics
  • 2021
Abstract This work studies the dynamics of linear non-modal waves in viscoelastic pipe flows of FENE-P fluids using transient growth and resolvent analyses. We particularly focus on the timeExpand
Exact Coherent States and the Nonlinear Dynamics of Wall-Bounded Turbulent Flows
Wall-bounded turbulence exhibits patterns that persist in time and space: coherent structures. These are important for transport processes and form a conceptual framework for important theoretical ...
Experimental observation of the origin and structure of elastoinertial turbulence
TLDR
The origin of EIT is determined in experiments and it is demonstrated that characteristic EIT structures can be detected across an unexpectedly wide range of parameters, suggesting that EIT plays as dominant a role in high-shear viscoelastic flows as ordinary turbulence does in high -inertia Newtonian flows. Expand
...
1
2
3
4
5
...