A multiscale method for micro/nano flows of high aspect ratio

JOURNAL OF COMPUTATIONAL PHYSICS

卷:233

Article

Borg, Matthew K.¹  Lockerby, Duncan A.²  Reese, Jason M.¹ 

[1] Univ Strathclyde, Dept Mech & Aerosp Engn, Glasgow G1 1XJ, Lanark, Scotland

[2] Univ Warwick, Sch Engn, Coventry CV4 7AL, W Midlands, England

关键词: Multiscale simulations;    Hybrid method;    Molecular dynamics;    Coupled solvers;    Scale-separation;   

DOI  :  10.1016/j.jcp.2012.09.009

来源: Elsevier

【 摘 要 】

We develop a new multiscale scheme for simulating micro/nano flows of high aspect ratio in the flow direction, e.g. within long ducts, tubes, or channels, of varying section. The scheme couples conventional hydrodynamic conservation equations for mass and momentum-flux with molecular dynamics (MD) in a unified framework. The method is very much different from common 'domain-decomposition' hybrid methods, and is more related to micro-resolution methods, such as the Heterogeneous Multiscale Method. We optimise the use of the computationally-costly MD solvers by applying them only at a limited number of streamwise-distributed cross-sections of the macroscale geometry. The greater the streamwise scale of the geometry, the more significant is the computational speed-up when compared to a full MD simulation. We test our new multiscale method on the case of a converging/diverging nanochannel conveying a simple Lennard-Jones liquid. We validate the results from our simulations by comparing them to a full MD simulation of the same test case. (C) 2012 Elsevier Inc. All rights reserved.

【 授权许可】

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