Molecular dynamics simulation of nanochannel flows with effects of wall lattice-fluid interactions

Abstract

In the present paper, molecular dynamics simulations are performed to explore the effects of wall lattice-fluid interactions on the hydrodynamic characteristics in nanochannels. Couette and Poiseuille flows of liquid argon with channel walls of face-centered cubic (fcc) lattice structure are employed as the model configurations. Truncated and shifted Lennard-Jones (LJ) 12-6 potentials for evaluations of fluid-fluid and wall-fluid interactions, and a nonlinear spring potential for wall-wall interaction, are used as interatomistic or molecular models. The hydrodynamics at various flow orientation angles with respect to channel walls of lattice planes (111), (100), and (110) are explored. The present work discloses that the effects of key parameters, such as wall density, lattice plane, flow orientation, and LJ interaction energy, have a very significant impact on the nanochannel flow characteristics. The related interfacial phenomena and the underlying physical mechanisms are explored and interpreted. These results are significant in the understanding of nanoscale hydrodynamics, as well as in various applications where an accurate nanoscale flow rate control is necessary.

Effect of the wall structure on nanochannel gas flow: A molecular dynamics study

“…An fcc (111) surface configuration results in the fastest velocity followed by the fcc (100) and (110) surface configurations. This order is the same as the liquid case reported by Soong et al (2007). Unlike liquid flow, gas flow has a monolayer adsorbed on the wall surface, as shown in Fig.…”

“…This concept was used by Beskok's group for confined fluids (Barisik and Beskok, 2011a) and gas flow (Barisik and Beskok, 2011b). Although the working fluid of Soong et al (2007) and Liu and Li (2009) was liquid argon, the above results indicate that the gas flow is affected not only by the magnitude of the wall-fluid interaction but also by the nanoscopic wall roughness.…”

“…From the results of MD simulations of channel flow of liquid argon, Soong et al (2007) suggested that the surface lattice configuration affects the slip length and flow rate. This indicates that even for the same wall structure, such as a face-centered cubic (fcc) structure, the flow in the vicinity of the wall is different for different surface configurations.…”

Modeling of Hydraulic Fracturing on the Basis of the Particle Method

“…A promising class of numerical methods for mechanics of a deformable solid body, adapted for modeling fracture processes, and in principle for the modeling of heterogeneous media, such as soil, is particle methods [13][14][15][16][17][18]. The theoretical basis for calculating the resulting crack, as well as known analytical models of the hydraulic fracturing process, are given in [19][20][21][22][23][24]. It should be noted that in the modern sense the term "particle methods" is collective and includes very diverse numerical methods, both relating to the classical representatives of the discrete approach in mechanics, and the meshless algorithms for numerical solution of the equations of continuum mechanics.…”

Generalizing Murray's law: An optimization principle for fluidic networks of arbitrary shape and scale

“…For more information, see the reviews by Gad-el-Hak, 29 Karniadakis et al, 34 and Conlisk. 35 The complexity of channel flow increases dramatically in such conditions, e.g., density layering can occur near to the bounding surface in nanoscale liquid channel flows 36 and Knudsen layers (kinetic boundary layers) can occur in rarefied-gas channel flows. 37 Furthermore, the stateof-the art simulation techniques for such flows-molecular dynamics for liquid and dense gas flows, 38 and the direct simulation Monte Carlo method for dilute gas flows 39 although accurate, are extremely computationally expensive.…”