Molecular Gas Dynamics Analysis of the Collapse of Microbubble Accompanied with Heat and Mass Transfer at Gas-Liquid Interface

2017 ◽  
Vol 2017 (0) ◽  
pp. W051002
Author(s):  
Kazumichi KOBAYASHI
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Gas Dynamics ◽  
Liquid Interface ◽  
Molecular Gas ◽  
Dynamics Analysis

Modeling of Simultaneous Gas Absorption and Evaporation of Large Droplet

2005 ◽  
Author(s):  
Tov Elperin ◽  
Andrew Fominykh ◽  
Boris Krasovitov
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Gaseous Phase ◽  
Method Of Lines ◽  
Material Balance ◽  
Liquid Interface ◽  
Rate Of Change ◽  
Gas Absorption ◽  
Gaseous Species ◽  
Essential Change

In this study we investigated numerically simultaneous heat and mass transfer during evaporation/condensation on the surface of a stagnant droplet in the presence of inert admixtures containing non-condensable solvable gas. The performed analysis is pertinent to slow droplet evaporation/condensation when Mach number is small (M≪1). The system of transient conjugate nonlinear energy and mass conservation equations was solved using anelastic approximation. Transport coefficients of the gaseous phase were calculated as functions of temperature and concentrations of gaseous species. Thermophysical properties of the liquid phase are assumed to be constant. Using the material balance at the droplet surface we obtained equations for Stefan velocity and the rate of change of the droplet radius taking into account the effect of solvable gas absorption at the gas-liquid interface. We derived also boundary conditions at gas-liquid interface taking into account the effect of gas absorption. The governing equations were solved using a method of lines. Numerical calculations showed essential change of the rates of heat and mass transfer in water droplet-air-water vapor system under the influence of solvable species in a gaseous phase. Consequently, the use of additives of solvable noncondensable gases to enhance the rate of heat and mass transfer in dispersed systems allows to increase the efficiency and reduce the size of gas-liquid contactors.

Molecular gas dynamics analysis of collapse and rebound of spherical bubble filled with vapor and gas

2016 ◽  
Vol 2016 (0) ◽  
pp. 0727
Author(s):  
Takahiro NAGAYAMA ◽  
Misaki KON ◽  
Kazumichi KOBAYASHI ◽  
Masao WATANABE ◽  
Hiroyuki FUJII ◽  
...  
Keyword(s):  
Gas Dynamics ◽  
Molecular Gas ◽  
Dynamics Analysis ◽  
Spherical Bubble

scholarly journals Molecular gas dynamics analysis on influence of non-condensable gas molecules on evaporation of vapor molecules

2019 ◽  
Vol 2019 (0) ◽  
pp. OS2-07
Author(s):  
Yosuke ITO ◽  
Kazumichi Kobayashi ◽  
Masao Watanabe ◽  
Hiroyuki Fujii ◽  
Tsuyoshi Totani
Keyword(s):  
Gas Dynamics ◽  
Molecular Gas ◽  
Dynamics Analysis ◽  
Gas Molecules

303 Establishment of Kinetic Boundary Conditions of Methanol and Water on the Basis of Molecular Gas Dynamics Analysis and Shock Tube Experiment(2)

2006 ◽  
Vol 2006 (0) ◽  
pp. _303-1_-_303-4_
Author(s):  
Kazumichi KOBAYASHI ◽  
Shunsuke WATANABE ◽  
Masashi INABA ◽  
Takeru YANO ◽  
Shigeo FUJIKAWA ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Shock Tube ◽  
Gas Dynamics ◽  
Molecular Gas ◽  
Dynamics Analysis ◽  
Kinetic Boundary ◽  
Shock Tube Experiment

Molecular gas dynamics analysis on condensation coefficient of vapour during gas–vapour bubble collapse

2018 ◽  
Vol 856 ◽  
pp. 1045-1063 ◽  
Author(s):  
Kazumichi Kobayashi ◽  
Takahiro Nagayama ◽  
Masao Watanabe ◽  
Hiroyuki Fujii ◽  
Misaki Kon
Keyword(s):  
Gas Dynamics ◽  
Gas Flow ◽  
Bubble Radius ◽  
Density Ratio ◽  
Bubble Collapse ◽  
Molecular Gas ◽  
Dynamics Analysis ◽  
Condensation Coefficient ◽  
Evaporation And Condensation ◽  
Gas Molecules

This study investigates the influence of the condensation coefficient of vapour on the collapse of a bubble composed of condensable gas (vapour) and non-condensable gas (NC gas). We simulated vapour and NC gas flow inside a bubble based on the molecular gas dynamics analysis in order to replicate the phase change (viz., evaporation and condensation) precisely, by changing the initial number density ratio of the NC gas and vapour, the initial bubble radius and the value of the condensation coefficient. The results show that the motion of the bubble is unaffected by the value of the condensation coefficient when that value is larger than approximately 0.4. We also discuss NC gas drift at the bubble wall during the final stage of the bubble collapse and its influence on the condensation coefficient. We conclude that vapour molecules can behave as NC gas molecules when the bubble collapses, owing to the large concentration of NC gas molecules at the gas–liquid interface. That is, the condensation coefficient reaches almost zero when the bubble collapses violently.

Simultaneous Heat and Mass Transfer During Evaporation/Condensation on the Surface of a Stagnant Droplet in the Presence of Inert Admixtures Containing Non-Condensable Solvable Gas

2005 ◽  
Author(s):  
Tov Elperin ◽  
Andrew Fominykh ◽  
Boris Krasovitov
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Gaseous Phase ◽  
Material Balance ◽  
Liquid Interface ◽  
Rate Of Change ◽  
Gas Absorption ◽  
Gaseous Species ◽  
Essential Change ◽  
Simultaneous Heat

In this study we investigated numerically simultaneous heat and mass transfer during evaporation/condensation on the surface of a stagnant droplet in the presence of inert admixtures containing non-condensable solvable gas. The performed analysis is pertinent to slow droplet evaporation/condensation when Mach number is small (M≪1). The system of transient conjugate nonlinear energy and mass conservation equations was solved using anelastic approximation. Transport coefficients of the gaseous phase were calculated as functions of temperature and concentrations of gaseous species. Thermophysical properties of the liquid phase are assumed to be constant. Using the material balance at the droplet surface we obtained equations for Stefan velocity and the rate of change of the droplet radius taking into account the effect of solvable gas absorption at the gas-liquid interface. We derived also boundary conditions at gas-liquid interface taking into account the effect of gas absorption. The governing equations were solved using a method of lines. Numerical calculations showed essential change of the rates of heat and mass transfer in water droplet-air-water vapor system under the influence of solvable species in a gaseous phase. Consequently, the use of additives of solvable noncondensable gases to enhance the rate of heat and mass transfer in dispersed systems allows to increase the efficiency and reduce the size of gas-liquid contactors.

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