Imperial College London
Alternate

ProfessorDemetriosPapageorgiou

Faculty of Natural Sciences, Department of Mathematics

Chair in Applied Maths and Mathematical Physics
 
 
 
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Contact

 

+44 (0)20 7594 8369d.papageorgiou Website

 
 
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Location

 

750Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Ray:2017:10.1016/j.jnnfm.2017.11.004,
author = {Ray, PK and Hauge, J and Papageorgiou, D},
doi = {10.1016/j.jnnfm.2017.11.004},
journal = {Journal of Non-Newtonian Fluid Mechanics},
pages = {17--27},
title = {Nonlinear interfacial instability in two-fluid viscoelastic Couette flow},
url = {http://dx.doi.org/10.1016/j.jnnfm.2017.11.004},
volume = {251},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Weakly-nonlinear interfacial instabilities in two-fluid planar Couette flow are investigated for the case where one layer is thin. Taking this thin-layer thickness as a small parameter, asymptotic analysis is used to derive a nonlinear evolution equation for the interface height valid for wavelengths that scale with the channel height. Consequently, the influence of the thick layer is felt through a non-local coupling term which is obtained by solving a system of linear equations which are a simplified viscoelastic analogue to the Orr–Sommerfeld equation. The evolution equation allows for the clear identification of the influence of normal stresses at the interface on both the initial instability and the subsequent nonlinear dynamics. Results from numerical simulations illustrate: (1) an array of non-stationary states including traveling waves and chaos, (2) competition between elastic instability and instability due to viscosity stratification, and (3) the accuracy of a simplified ’localized’ evolution equation (derived using a long-wave approximation to the coupling term) when either the elasticity of the thick-layer fluid is sufficiently weak or the elasticities of the two fluids are sufficiently well-matched.
AU  - Ray,PK
AU  - Hauge,J
AU  - Papageorgiou,D
DO  - 10.1016/j.jnnfm.2017.11.004
EP  - 27
PY  - 2017///
SN  - 0377-0257
SP  - 17
TI  - Nonlinear interfacial instability in two-fluid viscoelastic Couette flow
T2  - Journal of Non-Newtonian Fluid Mechanics
UR  - http://dx.doi.org/10.1016/j.jnnfm.2017.11.004
UR  - http://hdl.handle.net/10044/1/56657
VL  - 251
ER  -
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