Heat transfer between infinite parallel plates in a rarefied gas

1972 ◽  
Vol 7 (1) ◽  
pp. 77-80 ◽  
Author(s):  
A. M. Bishaev ◽  
V. A. Rykov
Keyword(s):  
Heat Transfer ◽  
Rarefied Gas ◽  
Parallel Plates

Simulation of Heat Transfer Across Rarefied Gas in Annular and Planar Geometries: Comparison of Navier-Stokes, S-Model and DSMC Methods Results

2015 ◽  
Author(s):  
Dilesh Maharjan ◽  
Mustafa Hadj-Nacer ◽  
Minh-Tuan Ho ◽  
Stefan K. Stefanov ◽  
Irina Graur ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Kinetic Equation ◽  
Rarefied Gas ◽  
Model Kinetic Equation ◽  
Parallel Plates ◽  
Coaxial Cylinders ◽  
Aspect Ratios ◽  
S Model ◽  
Analytical Expressions

Steady state heat transfer through a rarefied gas confined between two parallel plates or two coaxial cylinders maintained at different temperatures is investigated using the nonlinear S-model kinetic equation and the DSMC technique for a large range of gas rarefaction. The profiles of heat flux, density and temperature are reported for different values of gas rarefaction parameter and given values of temperature and aspect ratios. In the slip regime the results of the S-model and DSMC technique are compared to the simulations performed using the Lin and Willis temperature jump boundary conditions at the at the solid surface implemented in ANSYS/Fluent CFD simulations. The analytical expressions for density number, temperature and heat flux in the free molecular regimes are obtained for both parallel plates and coaxial cylinders geometries with hot and cold surfaces having different values of the thermal accommodation coefficient. The solutions of these analytical expressions are compared to the S-model kinetic equation and DSMC technique results in the free molecular regime.

Effects of Triangular Rough Elements on Flow and Heat Transfer in Micro-Channels

2008 ◽  
Author(s):  
Yan-Hui Feng ◽  
Ai-Guo Wang ◽  
Lin Lin ◽  
Xin-Xin Zhang ◽  
Xin Liu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Rarefied Gas ◽  
Flow Direction ◽  
Leeward Side ◽  
Parallel Plates ◽  
Gas Temperature ◽  
Local Pressure ◽  
Flow And Heat Transfer ◽  
Micro Channels

The flow and heat transfer of rarefied gas in rough microchannels, which are confined between two infinite large parallel plates with uniformly distributed triangular rough elements, are simulated by DSMC method with Delaunay triangulation meshes. Analysis and comparison are carried out on smooth and rough channels with rough elements of different size or/and distribution density. Roughness in micro-channels affect the gas flow and heat transfer greatly. As the size or/and the number of rough elements increases, the gas velocity jumps more seriously, even being accompanied by some vortices; furthermore, the gas temperature increases, but both the mass flux and the heat transfer rate decrease. In the flow direction, the gas temperature rises first and then falls; the local pressure increases at the windward of rough elements and decreases at the leeward side; moreover, the heat flux at the surface shows violent fluctuation, that is, the heat flux at the rough element surface is much smaller than that at the channel wall surface.

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