Effect of surface roughness on slip flows in hydrophobic and hydrophilic microchannels by molecular dynamics simulation

Yang, Sheng; Fang, Liang

doi:10.1080/08927020500423778

Cited by 30 publications

(32 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a previous study (Yang and Fang 2005), MD simulations were performed to investigate the parameters controlling the degree of slip, the dependence of slip length, and the shear rate for simple fluids with atomic surface roughness in hydrophobic and hydrophilic microchannels. In the current work, the flow behavior and the slip length are examined for simple fluids confined between two parallel solid walls.…”

Section: Simulation Methodsmentioning

confidence: 99%

“…The purpose of this paper is to examine the effects of surface wettability and roughness of the surface on the nanoscale flow behavior and the boundary slip by MD simulation. The nanoscale roughness of the surface considered in this study is characterized by the solid wall decorated with periodic nanostrips on the surface, which is different from those in Yang and Fang (2005). The dependence of wall slip and flow rate is also discussed with various boundary conditions.…”

mentioning

confidence: 98%

“…In our previous work (Yang and Fang 2005), we have shown by MD simulation that the slip lengths of simple fluids are affected by the atomic roughness of the surface and the solid-fluid interaction. The degree of slip was found to decrease with surface roughness for both the hydrophobic and hydrophilic surfaces.…”

mentioning

confidence: 99%

“…They demonstrated that a significant drag reduction could be achieved because of the shear-free regions at the liquid-air interface. The effects of surface roughness on the slip and the rheological properties between solid walls were also examined by MD simulation (Gao et al 2000;Jabbarzadeh et al 2000;Cottin-Bizonne et al 2003Galea and Attard 2004;Yang and Fang 2005). Cottin-Bizonne et al (2003 have shown that the degree of wall slip is strongly affected by the surface heterogeneity and is a function of pressure for a non-wetting patterned surface.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Effects of surface roughness and interface wettability on nanoscale flow in a nanochannel

Yang

2006

Microfluid Nanofluid

Self Cite

105

View full text Add to dashboard Cite

Non-equilibrium molecular dynamics simulations have been carried out to investigate the effect of surface roughness and interface wettability on the nanorheology and slip boundary condition of simple fluids in a nanochannel of several atomic diameters width. The solid surfaces decorated with periodic nanostrips are considered as the rough surface in this study. The simulation results showed that the interface wettability and the surface roughness are important in determining the nanorheology of the nanochannel and fluid slip at solid-fluid interface. It is observed that the presence of surface roughness always suppresses the fluid slip for hydrophilic and hydrophobic surface nanochannels. For fluids over smooth and hydrophobic surfaces, the snapshots of fluid molecules show that an air gap or nanobubble exists at the fluid-solid interface, resulting in the apparent slip velocity. For a given surface with fixed interface wettability, the fluid velocities increase by increasing the driving force, while the driving force has no significant influence on the density structure of fluid molecules. The fluid slip and the flow rate are measured for hydrophilic and hydrophobic nanochannels. The flow rates in rough surface nanochannels are smaller than those of smooth surface walls due to the increase of drag resistance at the solid-fluid interface. The dependence between fluid slip and flow rate showed that the slip length increases approximately linearly with the flow rate for both the hydrophobic and hydrophilic surface nanochannels.

show abstract

Section: Simulation Methodsmentioning

confidence: 99%

mentioning

confidence: 98%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Effects of surface roughness and interface wettability on nanoscale flow in a nanochannel

Yang

2006

Microfluid Nanofluid

Self Cite

105

View full text Add to dashboard Cite

show abstract

“…The choice is based on the evidence 82,83 that the slip length δ depends on the wettability as δ ∝ 1/ε 2 , and we expect the similar dependence for ∆R. In addition the dependence of ∆R on the capillary roughness (13) shows a linear decay 84 suggesting that the difference ∆R can be expressed as Here ∆R 0 is the asymptotic value of ∆R for ε → ∞ and R → 0 and k ε , k R are numerical coefficients. k ε = 5.07 ± 1.01 was obtained by fitting the data in 12, and k R = −1.00±0.18 by fitting the data in 13.…”

mentioning

confidence: 99%

Spontaneous Imbibition in Nanopores of Different Roughness and Wettability

Stukan¹,

Ligneul²,

Crawshaw³

et al. 2010

Langmuir

102

107

View full text Add to dashboard Cite

The spontaneous imbibition of liquid in nanopores of different roughness is investigated using coarse grain Molecular Dynamics (MD) simulation. The numerical model is presented and the simplifying assumptions are discussed in detail. The molecular-kinetic theory introduced by Blake is used to describe the effect of dynamic contact angle on fluid imbibition. The capillary roughness is modeled using a random distribution of coarse grained particles forming the wall. The Lucas-Washburn equation is used as a reference for analyzing the imbibition curves obtained by simulation. Due to the statistical nature of MD processing, a comprehensive approach was made to average and smooth the data to accurately define a contact angle. The results are discussed in terms of effective hydrodynamic and static capillary radii and their difference as a function of roughness and wettability.

show abstract

Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

Priezjev

2012

Microfluid Nanofluid

View full text Add to dashboard Cite

The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.

show abstract

Effect of surface roughness on slip flows in hydrophobic and hydrophilic microchannels by molecular dynamics simulation

Cited by 30 publications

References 23 publications

Effects of surface roughness and interface wettability on nanoscale flow in a nanochannel

Effects of surface roughness and interface wettability on nanoscale flow in a nanochannel

Spontaneous Imbibition in Nanopores of Different Roughness and Wettability

Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions

Contact Info

Product

Resources

About