Lattice Boltzmann simulations of apparent slip in hydrophobic microchannels

Abstract

Various experiments have found a boundary slip in hydrophobic microchannel flows, but a consistent understanding of the results is still lacking. While Molecular Dynamics (MD) simulations cannot reach the low shear rates and large system sizes of the experiments, it is often impossible to resolve the needed details with macroscopic approaches. We model the interaction between hydrophobic channel walls and a fluid by means of a multi-phase lattice Boltzmann model. Our mesoscopic approach overcomes the limitations of MD simulations and can reach the small flow velocities of known experiments. We reproduce results from experiments at small Knudsen numbers and other simulations, namely an increase of slip with increasing liquid-solid interactions, the slip being independent of the flow velocity, and a decreasing slip with increasing bulk pressure. Within our model we develop a semi-analytic approximation of the dependence of the slip on the pressure.

arXiv comment7 pages, 4 figures

References in corpus (7)

• Simulation of non-ideal gases and liquid-gas phase transitions by lattice Boltzmann equation
• Boundary conditions at a fluid - solid interface
• Dynamics of simple liquids at heterogeneous surfaces : Molecular Dynamics simulations and hydrodynamic description
• Nanorheology : an Investigation of the Boundary Condition at Hydrophobic and Hydrophilic Interfaces
• Lattice Boltzmann method at finite-Knudsen numbers
• Mesoscopic two-phase model for describing apparent slip in micro-channel flows
• The no-slip condition for a mixture of two liquids

Cited by in corpus (25)

• Generalized Lattice Boltzmann Method with multi-range pseudo-potential
• Mesoscopic modeling of a two-phase flow in the presence of boundaries: the Contact Angle
• Slip flow over structured surfaces with entrapped microbubbles
• Slip at Fluid-Solid Interface
• From Bijels to Pickering emulsions: a lattice Boltzmann study
• The lattice Boltzmann method for isothermal micro-gaseous flow and its application in shale gas flow: a review
• Wetting, roughness and flow boundary conditions
• Roughness induced boundary slip in microchannel flows
• Fluid velocity slip and temperature jump at a solid surface
• Random-roughness hydrodynamic boundary conditions
• Tensorial slip of super-hydrophobic channels
• Contact angle determination in multicomponent lattice Boltzmann simulations
• Lattice Boltzmann simulations in microfluidics: probing the no-slip boundary condition in hydrophobic, rough, and surface nanobubble laden microchannels
• Simulations of slip flow on nanobubble-laden surfaces
• Capillary filling with pseudo-potential binary Lattice-Boltzmann model
• Capillary filling with wall corrugations] Capillary filling in microchannels with wall corrugations: A comparative study of the Concus-Finn criterion by continuum, kinetic and atomistic approaches
• Evidence of thin-film precursors formation in hydrokinetic and atomistic simulations of nano-channel capillary filling
• Simulation of fluid flow in hydrophobic rough microchannels
• Flow past superhydrophobic surfaces with cosine variation in local slip length
• Contact angle dependence on the fluid-wall dispersive energy
• A boundary condition with adjustable slip length for Lattice Boltzmann simulations
• Diffusion dominated evaporation in multicomponent lattice Boltzmann simulations
• Hydrokinetic simulations of nanoscopic precursor films in rough channels
• Slip flow regimes in nanofluidics: a universal superexponential model
• A sharp interface approach for wetting dynamics of coated droplets and soft particles