Influence of the atomic weight of the target on the magnitude of the energy accommodation coefficient of ions of a partially ionized gas flow

1979 ◽  
Vol 20 (3) ◽  
pp. 325-328 ◽  
Author(s):  
V. A. Shuvalov
Keyword(s):  
Gas Flow ◽  
Atomic Weight ◽  
Accommodation Coefficient ◽  
Ionized Gas ◽  
Energy Accommodation ◽  
Partially Ionized

A Molecular Dynamics Study on Energy Accommodation Coefficients in Microchannels

2008 ◽  
Author(s):  
Jun Sun ◽  
Zhixin Li
Keyword(s):  
Temperature Difference ◽  
Wall Temperature ◽  
Gas Flow ◽  
Accommodation Coefficient ◽  
Energy Accommodation ◽  
Micro Gas Flow ◽  
Different Temperatures ◽  
Accommodation Coefficients ◽  
Lower Temperature ◽  
Non Equilibrium

Energy accommodation coefficient (EAC), used in thermal boundary condition in micro gas flow and heat transfer, is reported to be always less than unity and greatly influenced by the wall characters. According to EAC’s definition, the statistical algorithm was described and EAC for argon gas was studied by two dimensional NEMD simulations with heat conduction between two smooth platinum plates at different temperatures. With one wall’s temperature fixed, the non-equilibrium EACs were calculated by changing the other wall’s temperature. Meanwhile, the equilibrium EAC at one temperature can be extrapolated from a series of non-equilibrium EACs as the temperature difference approaches to zero. The effects of wall temperature, wall temperature difference, and Kn on EAC were investigated. Non-equilibrium EAC increases with wall temperature difference decreased, and becomes larger with increased Kn. And equilibrium EAC is larger for lower temperature and larger Kn.

Partially Ionized Gas Flow and Heat Transfer in the Separation, Reattachment, and Redevelopment Regions Downstream of an Abrupt Circular Channel Expansion

1972 ◽  
Vol 94 (1) ◽  
pp. 119-127 ◽  
Author(s):  
L. H. Back ◽  
P. F. Massier ◽  
E. J. Roschke
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Reverse Flow ◽  
Vortex Sheet ◽  
Good Prediction ◽  
Ionized Gas ◽  
Energy Fraction ◽  
High Enthalpy ◽  
Channel Expansion ◽  
Partially Ionized

Heat transfer and pressure measurements obtained in the separation, reattachment, and redevelopment regions along a tube and nozzle located downstream of an abrupt channel expansion are presented for a very high enthalpy flow of argon. The ionization energy fraction extended up to 0.6 at the tube inlet just downstream of the arc heater. Reattachment resulted from the growth of an instability in the vortex sheet-like shear layer between the central jet that discharged into the tube and the reverse flow along the wall at the lower Reynolds numbers, as indicated by water flow visualization studies which were found to dynamically model the high-temperature gas flow. A reasonably good prediction of the heat transfer in the reattachment region where the highest heat transfer occurred and in the redevelopment region downstream can be made by using existing laminar boundary layer theory for a partially ionized gas. In the experiments as much as 90 percent of the inlet energy was lost by heat transfer to the tube and the nozzle wall.

Study on Effect of Momentum and Energy Accommodation Coefficient on Flow Properties

2018 ◽  
Author(s):  
Kishore Kumar Kammara ◽  
Arun Kumar Chinnappan ◽  
Rakesh Kumar
Keyword(s):  
Accommodation Coefficient ◽  
Flow Properties ◽  
Energy Accommodation

Slightly Rarefied Gas Flow over a Body with Small Accommodation Coefficient

1979 ◽  
Vol 47 (2) ◽  
pp. 663-671 ◽  
Author(s):  
Kazuo Aoki ◽  
Takaji Inamuro ◽  
Yoshimoto Onishi
Keyword(s):  
Gas Flow ◽  
Rarefied Gas ◽  
Accommodation Coefficient ◽  
Rarefied Gas Flow ◽  
Slightly Rarefied Gas

Exploring the nonextensive thermodynamics of partially ionized gas in magnetic field

2021 ◽  
Vol 104 (4) ◽  
Author(s):  
June Young Kim ◽  
Hyo-Chang Lee ◽  
Geunwoo Go ◽  
Yeong Hwan Choi ◽  
Y. S. Hwang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ionized Gas ◽  
Nonextensive Thermodynamics ◽  
Partially Ionized

The Effects of Hall and Ion Slip on the Electrical Conductivity of Partially Ionized Gases for Magnetohydrodynamic Re-Entry Vehicle Application

1962 ◽  
Vol 84 (2) ◽  
pp. 177-184 ◽  
Author(s):  
M. J. Brunner
Keyword(s):  
Electrical Conductivity ◽  
Cross Sections ◽  
Effective Conductivity ◽  
Ionized Gas ◽  
Equilibrium Conditions ◽  
Degree Of Ionization ◽  
Slip Effects ◽  
Wide Range ◽  
Ion Slip ◽  
Partially Ionized

The presence of a partially ionized gas around a hypersonic vehicle permits the application of magnetohydrodynamic (MHD) devices during re-entry. The operation of such MHD devices on a re-entry vehicle will largely depend on the magnitude of the electrical conductivity of the gas between the electrodes. In some cases it may be necessary to seed the air in order to insure high conductivity. The operation of the re-entry vehicle at relatively low gas densities and high magnetic fields will produce Hall and ion slip effects which may materially reduce the effective conductivity between the electrodes. The electrical conductivity including Hall and ion slip effects for air is presented for a wide range of pressures and temperatures and for a typical re-entry vehicle, with and without seeding. The electrical conductivity is evaluated for equilibrium conditions considering the number density and collision cross sections for electrons, neutrals, and ions. The Hall and ion slip effects are evaluated from the degree of ionization, the cyclotron frequency, and the time between collisions for electrons, neutrals, and ions.

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