Imperial College London
Alternate

prof paul f. luckham

Faculty of Engineering, Department of Chemical Engineering

Professor in Particle Technology
 
 
 
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Contact

 

+44 (0)20 7594 5583p.luckham01 Website

 
 
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Assistant

 

Miss Jessica Baldock +44 (0)20 7594 5699

 
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Location

 

104Roderic Hill BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Ekanem:2020:10.1103/PhysRevE.101.042605,
author = {Ekanem, EM and Berg, S and De, S and Fadili, A and Bultreys, T and Rucker, M and Southwick, J and Crawshaw, J and Luckham, PF},
doi = {10.1103/PhysRevE.101.042605},
journal = {Physical Review E: Statistical, Nonlinear, and Soft Matter Physics},
pages = {042605  1--042605  14},
title = {Signature of elastic turbulence of viscoelastic fluid flow in a single pore throat},
url = {http://dx.doi.org/10.1103/PhysRevE.101.042605},
volume = {101},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - When a viscoelastic fluid, such as an aqueous polymer solution, flows through a porous medium, the fluid undergoes a repetitive expansion and contraction as it passes from one pore to the next. Above a critical flow rate, the interaction between the viscoelastic nature of the polymer and the pore configuration results in spatial and temporal flow instabilities reminiscent of turbulentlike behavior, even though the Reynolds number Re1. To investigate whether this is caused by many repeated pore body–pore throat sequences, or simply a consequence of the converging (diverging) nature present in a single pore throat, we performed experiments using anionic hydrolyzed polyacrylamide (HPAM) in a microfluidic flow geometry representing a single pore throat. This allows the viscoelastic fluid to be characterized at increasing flow rates using microparticle image velocimetry in combination with pressure drop measurements. The key finding is that the effect, popularly known as “elastic turbulence,” occurs already in a single pore throat geometry. The critical Deborah number at which the transition in rheological flow behavior from pseudoplastic (shear thinning) to dilatant (shear thickening) strongly depends on the ionic strength, the type of cation in the anionic HPAM solution, and the nature of pore configuration. The transition towards the elastic turbulence regime was found to directly correlate with an increase in normal stresses. The topology parameter, Qf, computed from the velocity distribution, suggests that the “shear thickening” regime, where much of the elastic turbulence occurs in a single pore throat, is a consequence of viscoelastic normal stresses that cause a complex flow field. This flow field consists of extensional, shear, and rotational features around the constriction, as well as upstream and downstream of the constriction. Furthermore, this elastic turbulence regime, has high-pressure fluctuations, with a power-law decay ex
AU  - Ekanem,EM
AU  - Berg,S
AU  - De,S
AU  - Fadili,A
AU  - Bultreys,T
AU  - Rucker,M
AU  - Southwick,J
AU  - Crawshaw,J
AU  - Luckham,PF
DO  - 10.1103/PhysRevE.101.042605
EP  - 1
PY  - 2020///
SN  - 1539-3755
SP  - 042605
TI  - Signature of elastic turbulence of viscoelastic fluid flow in a single pore throat
T2  - Physical Review E: Statistical, Nonlinear, and Soft Matter Physics
UR  - http://dx.doi.org/10.1103/PhysRevE.101.042605
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000527889100011&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://journals.aps.org/pre/abstract/10.1103/PhysRevE.101.042605
UR  - http://hdl.handle.net/10044/1/81616
VL  - 101
ER  -
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