The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform
John Robert Torczynski - One of the best experts on this subject based on the ideXlab platform.
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Thermophoresis in Rarefied Gas Flows
AIP Conference Proceedings, 2003Co-Authors: Daniel J. Rader, Michail A. Gallis, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a motionless, spherical particle suspended in a quiescent, Rarefied Gas between parallel plates of unequal temperature. The Rarefied‐Gas heat flux and temperature profiles are calculated with the Direct Simulation Monte Carlo (DSMC) method, which provides a time‐averaged, spatially resolved approximation to the molecular velocity distribution. A force Green’s function is used to calculate the spatial and pressure dependence of the thermophoretic force directly from the computed velocity distribution.
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Thermophoresis in Rarefied Gas Flows
Aerosol Science and Technology, 2002Co-Authors: Michail A. Gallis, Daniel J. Rader, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a free-molecular, motionless, spherical particle suspended in a Rarefied Gas flow between parallel plates of unequal temperature. The Rarefied Gas flow is calculated with the direct simulation Monte Carlo (DSMC) method, which provides a time-averaged approximation to the local molecular velocity distribution at discrete locations between the plates. A force Green's function is used to calculate the thermophoretic force directly from the DSMC simulations for the molecular velocity distribution, with the under-lying assumption that the particle does not influence the molecular velocity distribution. Perfect accommodation of energy and momentum is assumed at all solid/Gas boundaries. Earlier work for monatomic Gases (helium and argon) is reviewed, and new calculations for a diatomic Gas (nitrogen) are presented. Gas heat flux and particle thermophoretic forces for argon, helium, and nitrogen are given for a 0.01 m spacing between pla...
Michail A. Gallis - One of the best experts on this subject based on the ideXlab platform.
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Thermophoresis in Rarefied Gas Flows
AIP Conference Proceedings, 2003Co-Authors: Daniel J. Rader, Michail A. Gallis, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a motionless, spherical particle suspended in a quiescent, Rarefied Gas between parallel plates of unequal temperature. The Rarefied‐Gas heat flux and temperature profiles are calculated with the Direct Simulation Monte Carlo (DSMC) method, which provides a time‐averaged, spatially resolved approximation to the molecular velocity distribution. A force Green’s function is used to calculate the spatial and pressure dependence of the thermophoretic force directly from the computed velocity distribution.
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Thermophoresis in Rarefied Gas Flows
Aerosol Science and Technology, 2002Co-Authors: Michail A. Gallis, Daniel J. Rader, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a free-molecular, motionless, spherical particle suspended in a Rarefied Gas flow between parallel plates of unequal temperature. The Rarefied Gas flow is calculated with the direct simulation Monte Carlo (DSMC) method, which provides a time-averaged approximation to the local molecular velocity distribution at discrete locations between the plates. A force Green's function is used to calculate the thermophoretic force directly from the DSMC simulations for the molecular velocity distribution, with the under-lying assumption that the particle does not influence the molecular velocity distribution. Perfect accommodation of energy and momentum is assumed at all solid/Gas boundaries. Earlier work for monatomic Gases (helium and argon) is reviewed, and new calculations for a diatomic Gas (nitrogen) are presented. Gas heat flux and particle thermophoretic forces for argon, helium, and nitrogen are given for a 0.01 m spacing between pla...
Daniel J. Rader - One of the best experts on this subject based on the ideXlab platform.
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Thermophoresis in Rarefied Gas Flows
AIP Conference Proceedings, 2003Co-Authors: Daniel J. Rader, Michail A. Gallis, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a motionless, spherical particle suspended in a quiescent, Rarefied Gas between parallel plates of unequal temperature. The Rarefied‐Gas heat flux and temperature profiles are calculated with the Direct Simulation Monte Carlo (DSMC) method, which provides a time‐averaged, spatially resolved approximation to the molecular velocity distribution. A force Green’s function is used to calculate the spatial and pressure dependence of the thermophoretic force directly from the computed velocity distribution.
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Thermophoresis in Rarefied Gas Flows
Aerosol Science and Technology, 2002Co-Authors: Michail A. Gallis, Daniel J. Rader, John Robert TorczynskiAbstract:Numerical calculations are presented for the thermophoretic force acting on a free-molecular, motionless, spherical particle suspended in a Rarefied Gas flow between parallel plates of unequal temperature. The Rarefied Gas flow is calculated with the direct simulation Monte Carlo (DSMC) method, which provides a time-averaged approximation to the local molecular velocity distribution at discrete locations between the plates. A force Green's function is used to calculate the thermophoretic force directly from the DSMC simulations for the molecular velocity distribution, with the under-lying assumption that the particle does not influence the molecular velocity distribution. Perfect accommodation of energy and momentum is assumed at all solid/Gas boundaries. Earlier work for monatomic Gases (helium and argon) is reviewed, and new calculations for a diatomic Gas (nitrogen) are presented. Gas heat flux and particle thermophoretic forces for argon, helium, and nitrogen are given for a 0.01 m spacing between pla...
Masaru Sugiyama - One of the best experts on this subject based on the ideXlab platform.
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ON THE TEMPERATURE OF A Rarefied Gas IN NON-EQUILIBRIUM
Meccanica, 1999Co-Authors: Elvira Barbera, Ingo Müller, Masaru SugiyamaAbstract:This paper addresses the problem of the proper definition of temperature of a Gas in non‐equilibrium. It shows that the mean kinetic energy of the atoms of a Rarefied Gas is not a good measure for thethermodynamic temperature, because in general it jumps at a wall, and because it is non‐monotone in a one‐dimensional process of stationary heat conduction. The jump of the ‘kinetic temperature’ is calculated and found to be about 5 K in a Rarefied Gas. The basis for the calculations is provided by the arguments of extended thermodynamics of 14 moments. An essential tool is the minimax principle of entropy production recently postulated by Struchtrup Weiss [1], because it furnishes one important boundary condition.
Tatsunori Tomota - One of the best experts on this subject based on the ideXlab platform.
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A force acting on an oblate spheroid with discontinuous surface temperature in a slightly Rarefied Gas
Journal of Fluid Mechanics, 2014Co-Authors: Kazuo Aoki, Shigeru Takata, Tatsunori TomotaAbstract:An oblate spheroid, the respective hemispheroids of which are kept at different uniform temperatures, placed in a Rarefied Gas at rest is considered. The explicit formula for the force acting on the spheroid (radiometric force) is obtained for small Knudsen numbers. This is a model of a vane of the Crookes radiometer. The analysis is performed for a general axisymmetric distribution of the surface temperature of the spheroid, allowing abrupt changes. Although the generalized slip flow theory, established by Sone ( Rarefied Gas Dynamics , vol. 1, 1969, pp. 243–253), is available for general Rarefied Gas flows at small Knudsen numbers, it cannot be applied to the present problem because of the abrupt temperature changes. However, if it is combined with the symmetry relations for the linearized Boltzmann equation developed recently by Takata ( J. Stat. Phys. , vol. 136, 2009, pp. 751–784), one can bypass the difficulty. To be more specific, the force acting on the spheroid in the present problem can be generated from the solution of the adjoint problem to which the generalized slip flow theory can be applied, i.e. the problem in which the same spheroid with a uniform surface temperature is placed in a uniform flow of a Rarefied Gas. The analysis of the present paper follows this strategy.
