Hybrid molecular-continuum simulations of water flow through carbon nanotube membranes of realistic thickness

Konstantinos Ritos, Matthew Karl Borg, Duncan A. Lockerby, David Emerson, Jason Reese

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

We present new hybrid molecular-continuum simulations of water flow through filtration membranes. The membranes consist of aligned carbon nanotubes (CNTs) of high aspect ratio, where the tube diameters are ~1–2 nm and the tube lengths (i.e. the membrane thicknesses) are 2–6 orders of magnitude larger than this. The flow in the CNTs is subcontinuum, meaning standard continuum fluid equations cannot adequately model the flow; also, full molecular dynamics (MD) simulations are too computationally expensive for modelling these membrane thicknesses. However, various degrees of scale separation in both time and space in this problem can be exploited by a multiscale method: we use the serial-network internal-flow multiscale method (SeN-IMM). Our results from this hybrid method compare very well with full MD simulations of flow cases up to a membrane thickness of 150 nm, beyond which any full MD simulation is computationally intractable. We proceed to use the SeN-IMM to predict the flow in membranes of thicknesses 150 nm–2 μm, and compare these results with both a modified Hagen–Poiseuille flow equation and experimental results for the same membrane configuration. We also find good agreement between experimental and our numerical results for a 1-mm-thick membrane made of CNTs with diameters around 1.1 nm. In this case, the hybrid simulation is orders of magnitude quicker than a full MD simulation would be.
LanguageEnglish
Pages997-1010
Number of pages14
JournalMicrofluidics and Nanofluidics
Volume19
Issue number5
Early online date10 Jul 2015
DOIs
Publication statusPublished - 30 Nov 2015

Fingerprint

Carbon Nanotubes
Flow of water
water flow
Nanotubes
Carbon nanotubes
Carbon
Continuum
Membrane
carbon nanotubes
membranes
continuums
Membranes
Water
Molecular Dynamics Simulation
Multiscale Methods
Molecular dynamics
Simulation
simulation
molecular dynamics
Internal Flow

Keywords

  • multiscale fluid dynamics
  • hybrid methods
  • molecular dynamics
  • scale separation
  • microfluidics
  • nanofluidics
  • nanotubes
  • membranes
  • coupling

Cite this

Ritos, Konstantinos ; Borg, Matthew Karl ; Lockerby, Duncan A. ; Emerson, David ; Reese, Jason. / Hybrid molecular-continuum simulations of water flow through carbon nanotube membranes of realistic thickness. In: Microfluidics and Nanofluidics. 2015 ; Vol. 19, No. 5. pp. 997-1010.
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Hybrid molecular-continuum simulations of water flow through carbon nanotube membranes of realistic thickness. / Ritos, Konstantinos; Borg, Matthew Karl; Lockerby, Duncan A. ; Emerson, David; Reese, Jason.

In: Microfluidics and Nanofluidics, Vol. 19, No. 5, 30.11.2015, p. 997-1010.

Research output: Contribution to journalArticle

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