Two-dimensional nonlinear advection-diffusion in a model of surfactant spreading on a thin liquid film

AbstractThis article studies a numerical scheme for solving two-dimensional variable-order time fractional nonlinear advection-diffusion equation with variable coefficients, where the variable-order fractional derivative is in the Caputo type. The main idea is expanding the solution in terms of the 2D Legendre wavelets (2D LWs) where the variable-order time fractional derivative is discretized. We describe the method using the matrix operators and then implement it for solving various types of fractional advection-diffusion equations. The experimental results show the computational efficiency of the new approach.

Download Full-text

Numerical Investigation of EHD Conduction Pumping of Liquid Film With Phase-Change

ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference, Volume 2 ◽

10.1115/ht2007-32117 ◽

2007 ◽

Author(s):

Miad Yazdani ◽

Jamal Seyed-Yagoobi

Keyword(s):

Heat Transfer ◽

Liquid Film ◽

Phase Change ◽

Flow System ◽

Thin Liquid Film ◽

Finite Thickness ◽

Constant Heat Flux ◽

Two Dimensional ◽

Enhanced Heat Transfer ◽

Constant Heat

Electrohydrodynamic (EHD) conduction pumping is associated with the heterocharge layers of finite thickness in the vicinity of the electrodes, generated by the process of dissociation of the neutral electrolytic species and recombination of the generated ions. This paper numerically investigates the EHD conduction pumping of a thin liquid film in the presence of phase change. The flow system comprises a liquid film flowing over a two-dimensional flat plate while the vapor phase extended far beyond the interface to result in almost motionless vapor. The channel is separated into four different sections: the entrance, electrode, evaporation, and downstream sections. The entrance, electrode and downstream regions are adiabatic while a constant heat flux is applied in the evaporation side. The concept of EHD conduction pumping of liquid film in the presence of phase change is demonstrated in this paper. The enhanced heat transfer due to conduction pumping is evaluated.

Download Full-text

Thickness distribution of molecularly thin liquid film over surface with two dimensional sinusoidal roughness by using molecular dynamics

The Proceedings of the Conference on Information Intelligence and Precision Equipment IIP ◽

10.1299/jsmeiip.2002.31 ◽

2002 ◽

Vol 2002 (0) ◽

pp. 31-36

Author(s):

Susumu Ogata ◽

Yasunaga Mitsuya ◽

Yasuji Ohshima

Keyword(s):

Molecular Dynamics ◽

Liquid Film ◽

Thickness Distribution ◽

Thin Liquid Film ◽

Two Dimensional

Download Full-text

Numerical Analysis on the Dropwise Condensation of a Binary Vapor Mixture

10.1115/imece2001/htd-24130 ◽

2001 ◽

Author(s):

Hirokuni Akiyama ◽

Takao Nagasaki ◽

Yutaka Ito

Keyword(s):

Numerical Simulation ◽

Liquid Film ◽

Thin Liquid Film ◽

Marangoni Effect ◽

Ethanol Vapor ◽

Surface Tension Gradient ◽

Two Dimensional ◽

Vapor Mixture ◽

Horizontal Wall ◽

Phase Equilibrium Condition

Abstract A numerical simulation was performed on the condensation of water and ethanol vapor mixture on a horizontal wall in a plane two-dimensional field. The analysis solves unsteady flow and heat-and-mass transfer both for liquid and vapor with the phase equilibrium condition at the interface, using FDM and boundary-fitted coordinates to track the deformation of interface. The calculation was started from a very thin smooth liquid film, and it was found that instability occurs when the film thickness reaches a certain value resulting in the formation of relatively small droplets. With the growth of the droplets, they coalesce into larger ones. Between the droplets an extremely thin liquid film exists, and the surface tension gradient sustains the droplets. With the increase of the wall subcooling the maximum droplet becomes large due to the increase of the Marangoni effect.

Download Full-text