scholarly journals Flow Studies of a Two-Dimensional Liquid Film Jet

1988 ◽  
Vol 31 (9) ◽  
pp. 2389-2389 ◽  
Author(s):  
M. Gharib ◽  
P. Derango
Keyword(s):  
Liquid Film ◽  
Two Dimensional

Dripping instability of a two-dimensional liquid film under an inclined plate

2021 ◽  
Vol 932 ◽  
Author(s):  
Guangzhao Zhou ◽  
Andrea Prosperetti
Keyword(s):  
Liquid Film ◽  
Initial Conditions ◽  
Strong Dependence ◽  
Bond Number ◽  
Quasi Equilibrium ◽  
Two Dimensional ◽  
Inclined Plate ◽  
Maximum Value ◽  
Critical Curvature ◽  
Rayleigh Taylor Instability

It is known that the dripping of a liquid film on the underside of a plate can be suppressed by tilting the plate so as to cause a sufficiently strong flow. This paper uses two-dimensional numerical simulations in a closed-flow framework to study several aspects of this phenomenon. It is shown that, in quasi-equilibrium conditions, the onset of dripping is closely associated with the curvature of the wave crests approaching a well-defined maximum value. When dynamic effects become significant, this connection between curvature and dripping weakens, although the critical curvature remains a useful reference point as it is intimately related to the short length scales promoted by the Rayleigh–Taylor instability. In the absence of flow, when the film is on the underside of a horizontal plate, the concept of a limit curvature is relevant only for small liquid volumes close to a critical value. Otherwise, the drops that form have a smaller curvature and a large volume. The paper also illustrates the peculiarly strong dependence of the dripping transition on the initial conditions of the simulations. This feature prevents the development of phase maps dependent only on the governing parameters (Reynolds number, Bond number, etc.) similar to those available for film flow on the upper side of an inclined plate.

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

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.

Electrohydrodynamic Conduction Pumping of Liquid Film in Horizontal Annular Configuration

2006 ◽  
Author(s):  
Miad Yazdani ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Liquid Film ◽  
Annular Flow ◽  
Body Force ◽  
Film Flow ◽  
Finite Thickness ◽  
Force Distribution ◽  
Two Dimensional ◽  
Axisymmetric Channel ◽  
Liquid Film Flow ◽  
Horizontal Interface

Electrohydrodynamic (EHD) conduction pumping is associated with the heterocharge layers of finite thickness in the vicinity of the electrodes, which are based on the process of dissociation of the neutral electrolytic species and recombination of the generated ions. This work numerically studies the electrically driven liquid film flow in horizontal annular configuration based on electric conduction phenomenon. The numerical domain considered is represented by a two dimensional developing axisymmetric channel flow of a liquid separated from vapor by a horizontal interface. Two electrode designs are selected for this study: zero drag and non-zero drag electrode configurations. Laminar formulation is utilized for annular flow in the absence of gravity. The electric field and electric body force distributions in axial and radial directions along with flow field and velocity profiles for two electrode designs are presented and fundamentally analyzed. IN addition to the above, similar but limited results are provided for EHD conduction pumping of liquid film in horizontal annular configuration in the presence of gravity. In this case, a k — ε model with near wall treatment is incorporated for turbulence distribution. The electric body force distribution in axial and radial directions and flow pattern are fundamentally illustrated.

Numerical Analysis on the Dropwise Condensation of a Binary Vapor Mixture

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.

Multiscale Simulation of Two-Dimensional Self-Organization of Nanoparticles in Liquid Film

2004 ◽  
Vol 43 (7A) ◽  
pp. 4434-4442 ◽  
Author(s):  
Masahiro Fujita ◽  
Hiroyuki Nishikawa ◽  
Tatsuya Okubo ◽  
Yukio Yamaguchi
Keyword(s):  
Liquid Film ◽  
Multiscale Simulation ◽  
Self Organization ◽  
Two Dimensional
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