Investigation on heat transfer between two coaxial cylinders for measurement of thermal accommodation coefficient

2012 ◽  
Vol 24 (6) ◽  
pp. 062002 ◽  
Author(s):  
Hiroki Yamaguchi ◽  
Kazuaki Kanazawa ◽  
Yu Matsuda ◽  
Tomohide Niimi ◽  
Alexey Polikarpov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Accommodation Coefficient ◽  
Coaxial Cylinders ◽  
Thermal Accommodation ◽  
Thermal Accommodation Coefficient

Design of an Experiment to Measure the Thermal Accommodation Coefficient Between Helium and Stainless-Steel in Concentric Cylinders

2015 ◽  
Author(s):  
Rachel Green ◽  
Mustafa-Hadj Nacer ◽  
Miles Greiner
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Stainless Steel ◽  
Temperature Difference ◽  
Rarefied Gas ◽  
Accommodation Coefficient ◽  
Theoretical Expression ◽  
Thermal Accommodation ◽  
Concentric Cylinders ◽  
Thermal Accommodation Coefficient

Heat transfer through a 1 mm gap between two concentric cylinders representing the gap between a fuel support basket and a canister is experimentally and numerically investigated. The objective of this work is to study rarefied gas heat transfer in a simple geometry, and to measure the thermal accommodation coefficient at the interface between stainless steel and rarefied helium. The thermal accommodation coefficient is used to characterize the interaction between gas molecules and wall at the molecular level. It is important to determine its value with precision for better determination of heat transfer at low pressure. The experimental procedure consists of measuring the temperature difference between the inner and outer cylinders as the pressure is decreased in the gap. By knowing the heat flux across the gap the thermal accommodation coefficient can be extracted from the theoretical expression relating the temperature difference to the radial heat flux. Three-dimensional simulations using the ANSYS/Fluent commercial code are conducted to assess on the design of the experimental apparatus. These simulations confirmed that the apparatus design is effective to study the heat transfer across rarefied gas and to determine the thermal accommodation coefficient for helium on stainless steel surface.

Adsorption-Based Thermal Rectifier

2015 ◽  
Author(s):  
Tadeh Avanessian ◽  
Gisuk Hwang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Thermal Energy ◽  
Transfer Rate ◽  
Energy Transport ◽  
Accommodation Coefficient ◽  
Thermal Rectification ◽  
Thermal Accommodation ◽  
Thermal Accommodation Coefficient ◽  
Thermal Energy Transport

Controlling thermal energy transport (thermal diode) for the desired direction is crucial to improve the efficiency of thermal energy transport, conversion, and storage systems as electrical diodes significantly impact on modern electronic systems. The degree of thermal rectification is measured by the difference between the heat transfer rate in favorable and unfavorable directions to the heat transfer rate in the unfavorable direction. A gas-filled, nano-gap structure with two different surface coatings is considered to design the thermal rectifier. In such a structure where the characteristic length scale is similar to the order of the mean free path of the fluid particles (Knudsen flow regime), the effective thermal conductivity is dominantly controlled by the gas-surface interaction, i.e., thermal accommodation coefficient. For the thermal rectification, the adsorption-based, nonlinear thermal accommodation coefficient change is a key design parameter. Here, these are examined using the kinetic theory for various pressure and temperature ranges. Optimal material selections are also discussed.

Design of an Experimental Apparatus to Measure the Thermal Accommodation Coefficient Between Stainless Steel Surfaces and Rarefied Helium

2014 ◽  
Author(s):  
Rachel Green ◽  
Ernesto T. Manzo ◽  
Mustafa Hadj Nacer ◽  
Miles Greiner
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Rarefied Gas ◽  
Accommodation Coefficient ◽  
Electric Heater ◽  
Cross Sectional ◽  
Thermal Accommodation ◽  
Experimental Apparatus ◽  
Thermal Accommodation Coefficient ◽  
Aluminum Cylinder

The objective of this work is to design an experimental apparatus that can acquire data to benchmark rarefied gas heat transfer simulations, and determine the thermal accommodation coefficient at the interface between the solid surfaces and the gas. The design consists of an aluminum cylinder with an electric heater at its centerline, and within a stainless-steel sheath, centered inside a cylindrical pressure vessel whose temperature is controlled using an external water jacket. There is 0.47-cm-wide helium-filled gap between the inner cylinder and vessel wall. For a given heat generation rate, the temperature difference across this gap will increase as the gas pressure decreases due to ratification. Thermocouples will be bonded to the vessel’s outer surface, and the inner surface of the sheath that surrounds the heated aluminum cylinder. Two, two-dimensional computational meshes of the apparatus (one cross sectional and the other cross sectional is offset) and one three-dimensional computational mesh are constructed. These models include heat generation within the electric heater, conduction within the solid and gas-filled regions, and radiation heat transfer across the gas, and rarefied gas thermal resistances at the solid/gas interfaces. These simulations show that the difference between the thermocouple temperatures and the surfaces of the helium filled gap are small compared to the temperature across the gap. This will allow this apparatus design to be used to effectively benchmark the ANSYS/Fluent simulations, and determine the thermal accommodation coefficient.

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 The interaction of atoms and molecules with solid surfaces VIII—The exchange of energy between a gas and a solid

1937 ◽  
Vol 158 (894) ◽  
pp. 269-279 ◽  
Keyword(s):  
Morse Potential ◽  
Accommodation Coefficient ◽  
Solid Surfaces ◽  
Adsorbed State ◽  
Thermal Accommodation ◽  
Special Cases ◽  
Thermal Accommodation Coefficient ◽  
The Right ◽  
Energy Interchange

In previous papers of this series the problem of energy interchange between a gas atom and a solid has been discussed for the case when the gas atom makes a transition between two adsorbed states or between an adsorbed state and a free state. In this paper we shall discuss the case of a transition between two free states and apply the results to the determination of the thermal accommodation coefficient. In recent years a number of theoretical papers on this subject have appeared, following the new and accurate experimental work of Roberts, who worked with helium and neon on tungsten. The authors, however, neglect, or only roughly take into account, the attractive field which is known to exist between the solid and the gas; the fact that atoms become adsorbed on the surface is clear evidence of the existence of such a field. In this paper we shall suppose that the interaction potentials between solid and gas atom can be represented by a Morse potential function, for it has the right characteristics; in that it is attractive at large distances and repulsive at small ones, and has a minimum in between. The formulae of this paper are accordingly more general than previous ones and contain them as special cases. They are applicable to experimental results such as those of neon on tungsten for which earlier theories would not be adequate.

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