Large eddy simulation of turbulent heat transfer in a non-isothermal channel : Effects of temperature-dependent viscosity and thermal conductivity
(2019) In International Journal of Thermal Sciences 146.- Abstract
In this work, we perform large eddy simulations (LES) to study the influence of variable viscosity and thermal conductivity on forced convection in a non-isothermal channel flow. To prevent thermal dilatational effect, the gas density is assumed to be constant. The temperature ratio T2/T1 is varied from 1.01 to 2.2, where T2 and T1 are the temperatures of hot and cold walls, respectively. The mean turbulent Reynolds number is kept the same at 395. The results indicated that the mean flow fields are significantly affected by the temperature-dependent fluid properties. Despite the modified velocity and temperature profiles, it is interesting to note that the molecular momentum and heat transport... (More)
In this work, we perform large eddy simulations (LES) to study the influence of variable viscosity and thermal conductivity on forced convection in a non-isothermal channel flow. To prevent thermal dilatational effect, the gas density is assumed to be constant. The temperature ratio T2/T1 is varied from 1.01 to 2.2, where T2 and T1 are the temperatures of hot and cold walls, respectively. The mean turbulent Reynolds number is kept the same at 395. The results indicated that the mean flow fields are significantly affected by the temperature-dependent fluid properties. Despite the modified velocity and temperature profiles, it is interesting to note that the molecular momentum and heat transport across the channel remain unchanged. Meanwhile, pronounced differences are exhibited for various turbulence statistics such as root-mean-square velocity and temperature fluctuations, Reynolds shear stress, and correlation between streamwise velocity and temperature. Compared with the isothermal flows, it is also found that the presence of the temperature gradient tends to diminish heat transfer. With increasing the temperature ratio, the Nusselt numbers for both sides are reduced. Moreover, the hot side has a higher Nusselt number than the one at the cold side.
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- author
- Wang, Lei LU ; Liu, Jian LU ; Hussain, Safeer LU and Sundén, Bengt LU
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Constant gas density, Large eddy simulation, Temperature gradient, Turbulent forced convection, Variable physical properties
- in
- International Journal of Thermal Sciences
- volume
- 146
- article number
- 106094
- publisher
- Elsevier
- external identifiers
-
- scopus:85072021993
- ISSN
- 1290-0729
- DOI
- 10.1016/j.ijthermalsci.2019.106094
- language
- English
- LU publication?
- yes
- id
- 9c669e99-1d74-473c-9e71-79e655af2a93
- date added to LUP
- 2019-09-16 09:04:23
- date last changed
- 2022-04-26 05:27:33
@article{9c669e99-1d74-473c-9e71-79e655af2a93,
abstract = {{<p>In this work, we perform large eddy simulations (LES) to study the influence of variable viscosity and thermal conductivity on forced convection in a non-isothermal channel flow. To prevent thermal dilatational effect, the gas density is assumed to be constant. The temperature ratio T<sub>2</sub>/T<sub>1</sub> is varied from 1.01 to 2.2, where T<sub>2</sub> and T<sub>1</sub> are the temperatures of hot and cold walls, respectively. The mean turbulent Reynolds number is kept the same at 395. The results indicated that the mean flow fields are significantly affected by the temperature-dependent fluid properties. Despite the modified velocity and temperature profiles, it is interesting to note that the molecular momentum and heat transport across the channel remain unchanged. Meanwhile, pronounced differences are exhibited for various turbulence statistics such as root-mean-square velocity and temperature fluctuations, Reynolds shear stress, and correlation between streamwise velocity and temperature. Compared with the isothermal flows, it is also found that the presence of the temperature gradient tends to diminish heat transfer. With increasing the temperature ratio, the Nusselt numbers for both sides are reduced. Moreover, the hot side has a higher Nusselt number than the one at the cold side.</p>}},
author = {{Wang, Lei and Liu, Jian and Hussain, Safeer and Sundén, Bengt}},
issn = {{1290-0729}},
keywords = {{Constant gas density; Large eddy simulation; Temperature gradient; Turbulent forced convection; Variable physical properties}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{International Journal of Thermal Sciences}},
title = {{Large eddy simulation of turbulent heat transfer in a non-isothermal channel : Effects of temperature-dependent viscosity and thermal conductivity}},
url = {{http://dx.doi.org/10.1016/j.ijthermalsci.2019.106094}},
doi = {{10.1016/j.ijthermalsci.2019.106094}},
volume = {{146}},
year = {{2019}},
}