Lattice Boltzmann Method Applied to Variable Thermal Conductivity Conduction and Radiation Problems

In order to deeply investigate the gas heat conduction of nanoporous aerogel, a model of gas heat conduction was established based on microstructure of aerogel. Lattice Boltzmann method was used to simulate the temperature distribution and gas thermal conductivity at different size, and the size effects of gas heat conduction have had been obtained under micro-scale conditions. It can be concluded that the temperature jump on the boundary was not obvious and the thermal conductivity remained basically constant when the value of Knudsen number was less than 0.01; as the value of Knudsen number increased from 0.01 to 0.1, there was a clear temperature jump on the boundary and the thermal conductivity tended to decrease and the effect of boundary scattering increased drastically, as the value of Knudsen number was more than 0.1, the temperature jump increased significantly on the boundary, furtherly, the thermal conductivity decreased dramatically, and the size effects were significantly.

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Approach for predicting effective thermal conductivity of aerogel materials through a modified lattice Boltzmann method

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2018.01.013 ◽

2018 ◽

Vol 132 ◽

pp. 730-739 ◽

Cited By ~ 16

Author(s):

Z.G. Qu ◽

Y.D. Fu ◽

Y. Liu ◽

L. Zhou

Keyword(s):

Thermal Conductivity ◽

Lattice Boltzmann Method ◽

Effective Thermal Conductivity ◽

Lattice Boltzmann ◽

Boltzmann Method

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Numerical simulation of nanoparticles size/aspect ratio effect on thermal conductivity of nanofluids using lattice Boltzmann method

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2020.105033 ◽

2020 ◽

pp. 105033

Author(s):

Hamed Tahmooressi ◽

Alibakhsh Kasaeian ◽

Adel Yavarinasab ◽

Ali Tarokh ◽

Mahan Ghazi ◽

...

Keyword(s):

Thermal Conductivity ◽

Numerical Simulation ◽

Aspect Ratio ◽

Lattice Boltzmann Method ◽

Lattice Boltzmann ◽

Ratio Effect ◽

Boltzmann Method

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Thin Film Phonon Heat Conduction by the Dispersion Lattice Boltzmann Method

ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference, Volume 3 ◽

10.1115/ht2007-32130 ◽

2007 ◽

Author(s):

Rodrigo A. Escobar ◽

Cristina H. Amon ◽

Amador M. Guzma´n

Keyword(s):

Thin Films ◽

Thermal Conductivity ◽

Heat Conduction ◽

Lattice Boltzmann Method ◽

Thermal Energy ◽

Lattice Boltzmann ◽

Energy Transport ◽

Time Dependent ◽

Boltzmann Method ◽

Thermal Energy Transport

Numerical simulations of time-dependent thermal energy transport in semiconductor thin films are performed using the Lattice Boltzmann Method applied to phonon transport. The discrete Lattice Boltzmann Method is derived from the continuous Boltzmann transport equation assuming nonlinear, frequency-dependent phonon dispersion for acoustic and optical phonons. Results indicate that the heat conduction in silicon thin films displays a transition from diffusive to ballistic energy transport as the characteristic length of the system becomes comparable to the phonon mean free path, and that the thermal energy transport process is characterized by the propagation of multiple, superimposed phonon waves. The methodology is used to characterize the time-dependent temperature profiles inside films of decreasing thickness. Thickness-dependent thermal conductivity values are computed based on steady-state temperature distributions obtained from the numerical models. It is found that reducing feature size into the subcontinuum regime decreases the thermal conductivity when compared to bulk values, at a higher rate than what was displayed by the Debye-based gray Lattice Boltzmann Method.

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