Theoretical model for the thermal conductivity of a packed bed of solid spheroids in the presence of a static gas, with no adjustable parameters except at low pressure and temperature

2002 ◽  
Vol 45 (20) ◽  
pp. 4151-4161 ◽  
Author(s):  
A.J. Slavin ◽  
V. Arcas ◽  
C.A. Greenhalgh ◽  
E.R. Irvine ◽  
D.B. Marshall
Keyword(s):  
Thermal Conductivity ◽  
Theoretical Model ◽  
Packed Bed ◽  
Low Pressure

A theoretical model for the estimation of the effective thermal conductivity of a packed bed of fine particles

1987 ◽  
Vol 35 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Shinya Hayashi ◽  
Katsuyuki Kubota ◽  
Hiroo Masaki ◽  
Yasunori Shibata ◽  
Kazuhide Takahashi
Keyword(s):  
Thermal Conductivity ◽  
Theoretical Model ◽  
Effective Thermal Conductivity ◽  
Fine Particles ◽  
Packed Bed

scholarly journals Experimental Study on Thermal Conductivity and Hardness of Cu and Ni Nanoparticle Packed Bed for Thermoelectric Application

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Zi-Zhen Lin ◽  
Cong-Liang Huang ◽  
Wen-Kai Zhen ◽  
Yan-Hui Feng ◽  
Xin-Xin Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Packed Bed ◽  
Thermoelectric Application

The Effect of Turbulence on Momentum and Heat Transport in Packed Beds with Low Tube to Particle Diameter Ratio

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
F. I. Molina-Herrera ◽  
C. O. Castillo-Araiza ◽  
H. Jiménez-Islas ◽  
F. López-Isunza
Keyword(s):  
Thermal Conductivity ◽  
Heat Transport ◽  
Mass Flux ◽  
Flow Model ◽  
Particle Diameter ◽  
Packed Bed ◽  
Diameter Ratio ◽  
Packed Beds ◽  
Measured Temperature ◽  
Orthogonal Collocation

Abstract This is a theoretical study about the influence of turbulence on momentum and heat transport in a packed-bed with low tube to particle diameter ratio. The hydrodynamics is given here by the time-averaged Navier-Stokes equations including Darcy and Forchheimer terms, plus a κ-ε two-equation model to describe a 2D pseudo-homogeneous medium. For comparison, an equivalent conventional flow model has also been tested. Both models are coupled to a heat transport equation and they are solved using spatial discretization with orthogonal collocation, while the time derivative is discretized by an implicit Euler scheme. We compared the prediction of radial and axial temperature observations from a packed-bed at particle Reynolds numbers (Rep) of 630, 767, and 1000. The conventional flow model uses effective heat transport parameters: wall heat transfer coefficient (hw) and thermal conductivity (keff), whereas the turbulent flow model includes a turbulent thermal conductivity (kt), estimating hw via least-squares with Levenberg-Marquardt method. Although predictions of axial and radial measured temperature profiles with both models show small differences, the calculated radial profiles of the axial velocity component are very different. We demonstrate that the model that includes turbulence compares well with mass flux measurements at the packed-bed inlet, yielding an error of 0.77 % in mass flux balance at Rep = 630. We suggest that this approach can be used efficiently for the hydrodynamics characterization and design and scale-up of packed beds with low tube to particle diameter ratio in several industrial applications.

scholarly journals The effect of particle shape on the packed bed effective thermal conductivity based on DEM with polyhedral particles on the GPU

2020 ◽  
Vol 219 ◽  
pp. 115584 ◽  
Author(s):  
Nicolin Govender ◽  
Paul W. Cleary ◽  
Mehran Kiani-Oshtorjani ◽  
Daniel N. Wilke ◽  
Chuan-Yu Wu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Particle Shape ◽  
Packed Bed ◽  
Polyhedral Particles

scholarly journals Investigation of thermal conductivity of single-wall carbon nanotubes

2011 ◽  
Vol 15 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahmoud Jafari ◽  
Majid Vaezzadeh ◽  
Momhamad Mansouri ◽  
Abazar Hajnorouzi
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Theoretical Model ◽  
Potential Energy ◽  
Experimental Results ◽  
Single Wall Carbon Nanotubes ◽  
Lattice Vibrations ◽  
Single Wall Carbon ◽  
Thermal Potential ◽  
Conductivity Behavior

In this paper, the thermal conductivity of Single-wall carbon nanotubes (SWCNTs) is determined by lattice vibrations (phonons) and free elections. The thermal conductivity of SWCNTs is modeled up to 8-300 K and the observed deviations in K-T figures of SWCNTs are explained in terms of phonon vibrations models. An suitable theoretical model is shown for thermal conductivity behavior with respect to temperature and is generalized for experimental results. This model enables us to calculate thermal conductivity SWNTs and Thermal Potential Energy (TPE).

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