scholarly journals High-temperature estimation of energy accommodation coefficient of gas molecules on the surface

1999 ◽  
Vol 3 (4) ◽  
pp. 456-457 ◽  
Author(s):  
I. S. Altman
Keyword(s):  
High Temperature ◽  
Accommodation Coefficient ◽  
Temperature Estimation ◽  
Energy Accommodation ◽  
Gas Molecules

Scattering Process of Gas Molecules on Vertically Aligned Single-Walled Carbon Nanotubes

2009 ◽  
Author(s):  
Ikuya Kinefuchi ◽  
Yushi Harada ◽  
Jumpei Kawasaki ◽  
Kei Ishikawa ◽  
Junichiro Shiomi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Energy Transfer ◽  
Single Walled Carbon Nanotubes ◽  
Accommodation Coefficient ◽  
Scattering Process ◽  
Single Walled Carbon ◽  
Energy Accommodation ◽  
Vertically Aligned ◽  
Gas Molecules ◽  
Walled Carbon Nanotubes

Scattering process of helium molecules on vertically aligned single-walled carbon nanotubes (VA-SWNTs) was investigated using the molecular beam technique. The samples were grown by alcohol catalytic CVD method and their thicknesses were approximately 0.1 and 4 μm. We found that the modification of quartz surface with VA-SWNT films significantly enhances the energy transfer between gas molecules and the surface at room temperature and makes the energy accommodation coefficient of helium, which tends to be small even for contaminated surfaces because of the large mass mismatch between helium and surface atom, close to unity. The high porosity of the film enables gas molecules to penetrate into the film and suffer multiple collisions with carbon nanotubes (CNTs), leading to the efficient energy transfer. Although the accommodation coefficient slightly decreases for the thinner film, it is still high enough for practical applications. Our results demonstrate a potential application of VA-SWNTs as nanoscale fin structures to enhance heat transfer between gas phase and solid surfaces in rarefied gas flows. As the surface temperature increases, however, the energy accommodation becomes less efficient. This would be attributed to the small adsorption energy, which could reduce the trapping probability of helium on CNT bundles.

scholarly journals Measurement of Thermal Accommodation Coefficients Using Laser-Induced Incandescence

2007 ◽  
Author(s):  
K. J. Daun ◽  
P. H. Mercier ◽  
G. J. Smallwood ◽  
F. Liu ◽  
Y. Le Page
Keyword(s):  
Deformation Rate ◽  
Surface Deformation ◽  
Accommodation Coefficient ◽  
Polyatomic Gases ◽  
Thermal Accommodation ◽  
Laser Induced Incandescence ◽  
Translational Mode ◽  
Accommodation Coefficients ◽  
Thermal Accommodation Coefficient ◽  
Gas Molecules

Laser-induced incandescence (LII) is used to measure the thermal accommodation coefficient between soot sampled from a well-characterized flame and various monatomic and polyatomic gases. These measurements show that the thermal accommodation coefficient between soot and monatomic gases increases with molecular mass due to the decreasing speed of incident gas molecules and corresponding decrease in surface deformation rate, and that energy is transferred preferentially from the surface to the translational mode of the polyatomic gas molecules over internal energy modes.

scholarly journals Energy Accommodation Coefficient Calculation Methodology Using State-to-State Catalysis Applied to Hypersonic Flows

AIAA Journal ◽  
2020 ◽  
Vol 58 (1) ◽  
pp. 278-290 ◽  
Author(s):  
Georgios Bellas-Chatzigeorgis ◽  
Paolo F. Barbante ◽  
Thierry E. Magin
Keyword(s):  
Accommodation Coefficient ◽  
Hypersonic Flows ◽  
Energy Accommodation ◽  
Calculation Methodology
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