Continuous Pathway between the Elasto-Inertial and Elastic Turbulent States in Viscoelastic Channel Flow

Viscoelastic plane Poiseuille flow is shown to become linearly unstable in the absence of inertia, in the limit of high elasticities, for ultradilute polymer solutions. While inertialess elastic instabilities have been predicted for curvilinear shear flows, this is the first ever report of a purely...

Full description

Saved in:
Bibliographic Details
Published in:Physical review letters 2021-09, Vol.127 (13), p.1-134502, Article 134502
Main Authors: Khalid, Mohammad, Shankar, V, Subramanian, Ganesh
Format: Article
Language:English
Subjects:
Channel flow
Drag reduction
Elastic instability
Elastic limit
Flow stability
Fluid flow
Laminar flow
Polymers
Reynolds number
Shear flow
Turbulence
Turbulent flow
Viscoelasticity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Viscoelastic plane Poiseuille flow is shown to become linearly unstable in the absence of inertia, in the limit of high elasticities, for ultradilute polymer solutions. While inertialess elastic instabilities have been predicted for curvilinear shear flows, this is the first ever report of a purely elastic linear instability in a rectilinear shear flow. The novel instability continues up to a Reynolds number (Re) of O(1000), corresponding to the recently identified elasto-inertial turbulent state believed to underlie the maximum-drag-reduced regime. Thus, for highly elastic ultradilute polymer solutions, a single linearly unstable modal branch may underlie transition to elastic turbulence at zero Re and to elasto-inertial turbulence at moderate Re, implying the existence of continuous pathways connecting the turbulent states to each other and to the laminar base state.
ISSN:0031-9007
1079-7114
DOI:10.1103/PhysRevLett.127.134502