Molecular gas dynamics on unsteady flow of binary gas mixture with evaporation and condensation

2019 ◽  
Author(s):  
Masashi Inaba ◽  
Takeru Yano
Keyword(s):  
Unsteady Flow ◽  
Gas Dynamics ◽  
Molecular Gas ◽  
Gas Mixture ◽  
Evaporation And Condensation ◽  
Binary Gas Mixture

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.

scholarly journals Influence of Casting Solvents on CO2/CH4 Separation Using Polysulfone Membranes

Membranes ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 286
Author(s):  
Roba M. Almuhtaseb ◽  
Ahmed Awadallah-F ◽  
Shaheen A. Al-Muhtaseb ◽  
Majeda Khraisheh
Keyword(s):  
High Efficiency ◽  
In Situ Synthesis ◽  
Separation Process ◽  
Polymeric Membranes ◽  
Gas Mixture ◽  
Manufacturing Cost ◽  
Binary Gas Mixture ◽  
Maximum Permeability ◽  
Polysulfone Membranes

Polysulfone membranes exhibit resistance to high temperature with low manufacturing cost and high efficiency in the separation process. The composition of gases is an important step that estimates the efficiency of separation in membranes. As membrane types are currently becoming in demand for CO2/CH4 segregation, polysulfone will be an advantageous alternative to have in further studies. Therefore, research is undertaken in this study to evaluate two solvents: chloroform (CF) and tetrahydrofuran (THF). These solvents are tested for casting polymeric membranes from polysulfone (PSF) to separate every single component from a binary gas mixture of CO2/CH4. In addition, the effect of gas pressure was conducted from 1 to 10 bar on the behavior of the permeability and selectivity. The results refer to the fact that the maximum permeability of CO2 and CH4 for THF is 62.32 and 2.06 barrer at 1 and 2 bars, respectively. Further, the maximum permeability of CF is 57.59 and 2.12 barrer at 1 and 2 bars, respectively. The outcome selectivity values are 48 and 36 for THF and CF at 1 bar, accordingly. Furthermore, the study declares that with the increase in pressure, the permeability and selectivity values drop for CF and THF. The performance for polysulfone (PSF) membrane that is manufactured with THF is superior to that of CF relative to the Robeson upper bound. Therefore, through the results, it can be deduced that the solvent during in-situ synthesis has a significant influence on the gas separation of a binary mixture of CO2/CH4.

scholarly journals Simulation of a two-dimensional binary gas mixture outflow into vacuum through a thin slit on the basis of direct solution of the Boltzmann kinetic equation

2021 ◽  
Vol 2056 (1) ◽  
pp. 012007
Author(s):  
S S Sitnikov ◽  
F G Tcheremissine ◽  
T A Sazykina
Keyword(s):  
Kinetic Equation ◽  
Boltzmann Kinetic Equation ◽  
Gas Mixture ◽  
Two Dimensional ◽  
Direct Solution ◽  
Steady State Regime ◽  
Collision Integrals ◽  
Flow Formation ◽  
Binary Gas Mixture ◽  
State Regime

Abstract Two-dimensional binary gas mixture outflow from a vessel into vacuum through a thin slit is studied on the basis of direct solution of the Boltzmann kinetic equation. For evaluation of collision integrals in the Boltzmann equation a conservative projection method is used. Numerical simulation of a two-dimensional argon-neon gas mixture outflow from a vessel into vacuum was performed. Graphs of mixture components flow rate dependence on time during the flow formation, as well as fields of molecular density and temperature for steady-state regime, were obtained.

Analysis of slip and temperature jump coefficients in a binary gas mixture

1991 ◽  
Vol 25 (6) ◽  
pp. 937-944 ◽  
Author(s):  
I. V. Volkov ◽  
V. S. Galkin
Keyword(s):  
Temperature Jump ◽  
Gas Mixture ◽  
Binary Gas Mixture

Black hole mass measurement in nearby galaxy using molecular gas dynamics

2016 ◽  
Author(s):  
Kyoko Onishi ◽  
Satoru Iguchi ◽  
Timothy Davis ◽  
Martin Bureau ◽  
Michele Cappellari ◽  
...  
Keyword(s):  
Black Hole ◽  
Gas Dynamics ◽  
Mass Measurement ◽  
Molecular Gas ◽  
Nearby Galaxy ◽  
Black Hole Mass
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