Thermal conductances in a collisionless gas between coaxial cylinders and concentric spheres

1967 ◽  
Vol 1 (2) ◽  
pp. 209-217 ◽  
Author(s):  
Yau Wu
Keyword(s):  
General Theory ◽  
Velocity Distribution ◽  
Thermal Conduction ◽  
Thermal Conductance ◽  
Coaxial Cylinders ◽  
Thermal Transpiration ◽  
Thermal Accommodation ◽  
Exact Theory ◽  
Concentric Spheres ◽  
Accommodation Coefficients

The thermal conductances in a collisionless gas between coaxial cylinders and concentric spheres have been obtained for arbitrary thermal accommodation coefficients. This exact theory is based on the general theory of thermal conduction of collisionless gas developed recently by Wu which has been established according to his revised theory of thermal transpiration. The classical theory of thermal conductance between coaxial cylinders by Knudsen and Von Smoluchowski is only accurate to the first power of the temperature difference in which the velocity distribution in the system is assumed to be nearly Maxwellian. However, in the present paper, it is unnecessary to make this usual assumption and the exact theory has been established according to the revised theory of thermal transpiration.

An experimental assembly for precise measurement of thermal accommodation coefficients

2011 ◽  
Vol 82 (3) ◽  
pp. 035120 ◽  
Author(s):  
Wayne M. Trott ◽  
Jaime N. Castañeda ◽  
John R. Torczynski ◽  
Michael A. Gallis ◽  
Daniel J. Rader
Keyword(s):  
Precise Measurement ◽  
Thermal Accommodation ◽  
Experimental Assembly ◽  
Accommodation Coefficients

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.

Plane Thermal Transpiration of a Rarefied Gas Between Two Walls of Maxwell-Type Boundaries With Different Accommodation Coefficients

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Toshiyuki Doi
Keyword(s):  
Boltzmann Equation ◽  
Mass Flow Rate ◽  
Knudsen Number ◽  
Mass Flow ◽  
Flow Rate ◽  
Poiseuille Flow ◽  
Rarefied Gas ◽  
Thermal Transpiration ◽  
Wide Range ◽  
Accommodation Coefficients

Plane thermal transpiration of a rarefied gas between two walls of Maxwell-type boundaries with different accommodation coefficients is studied based on the linearized Boltzmann equation for a hard-sphere molecular gas. The Boltzmann equation is solved numerically using a finite difference method, in which the collision integral is evaluated by the numerical kernel method. The detailed numerical data, including the mass and heat flow rates of the gas, are provided over a wide range of the Knudsen number and the entire range of the accommodation coefficients. Unlike in the plane Poiseuille flow, the dependence of the mass flow rate on the accommodation coefficients shows different characteristics depending on the Knudsen number. When the Knudsen number is relatively large, the mass flow rate of the gas increases monotonically with the decrease in either of the accommodation coefficients like in Poiseuille flow. When the Knudsen number is small, in contrast, the mass flow rate does not vary monotonically but exhibits a minimum with the decrease in either of the accommodation coefficients. The mechanism of this phenomenon is discussed based on the flow field of the gas.

Formula for Thermal Accommodation Coefficients

1967 ◽  
Vol 46 (6) ◽  
pp. 2376-2386 ◽  
Author(s):  
Frank O. Goodman ◽  
Harold Y. Wachman
Keyword(s):  
Thermal Accommodation ◽  
Accommodation Coefficients

Upper Bounds to Carbon Nanotube Thermal Conduction and Entropy Flow

2005 ◽  
Author(s):  
N. Mingo ◽  
D. A. Broido
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Conduction ◽  
Thermal Conductance ◽  
Single Walled Carbon Nanotubes ◽  
Upper Bounds ◽  
Entropy Flow ◽  
Stringent Limit ◽  
Different Diameters ◽  
Walled Carbon Nanotubes ◽  
Theoretical Simulations

Quantum upper bounds to thermal conductance are computed for zigzag single walled carbon nanotubes of different diameters. Upper bounds to energy and entropy flow are also computed. The results impose a stringent limit on the maximum values that any experiment or simulation could obtain. Some previous theoretical simulations have violated the theoretical maxima.

Sign in / Sign up

Export Citation Format

Share Document