Cover Image

The onset of transient convection in bottom heated porous media

The theory of transient convection in bottom heated porous media under constant heat flux (CHF) condition or fixed surface temperature (FST) condition is advanced and verified by computational fluid dynamics (CFD) simulations. The use of κ*, instead of κ m tends to artificially inflate the value of...

Full description

Saved in:
Bibliographic Details
Main Authors: Tan, Ka-Kheng, Sam, Torng, Jamaludin, Hishamuddin
Format: Article
Language:English
Published: Elsevier Science 2003
Online Access:http://psasir.upm.edu.my/id/eprint/114575/1/114575.pdf
http://psasir.upm.edu.my/id/eprint/114575/
https://linkinghub.elsevier.com/retrieve/pii/S0017931003000450
Tags: Add Tag
No Tags, Be the first to tag this record!
id my.upm.eprints.114575
record_format eprints
spelling my.upm.eprints.1145752025-03-05T00:59:09Z http://psasir.upm.edu.my/id/eprint/114575/ The onset of transient convection in bottom heated porous media Tan, Ka-Kheng Sam, Torng Jamaludin, Hishamuddin The theory of transient convection in bottom heated porous media under constant heat flux (CHF) condition or fixed surface temperature (FST) condition is advanced and verified by computational fluid dynamics (CFD) simulations. The use of κ*, instead of κ m tends to artificially inflate the value of Rayleigh number by about 30%. A new transient Rayleigh number for unsteady-state heat conduction was defined to predict the onset of transient convection in porous media, which were successfully simulated. The critical transient Rayleigh number from the simulation for CHF was about 29.60, which is close to the theoretical value of 27.1 calculated by Ribando and Torrance in 1976. In the case of FST, the critical transient Rac was found to be 30.9, which is close to the theoretical value of 32.3. The critical times of onset for simulations were predicted with good accuracy. The prediction of the critical wavelengths of the emerging plumes were fair for the 2D simulations. Any experiment to verify the linear stability analysis for thermal instability must simultaneously concur in the three eigenvalue parameters, namely the Biot number, the critical wavenumber and the corresponding critical Rayleigh number, apart from the physical boundaries. The average maximum transient Nusselt number was found to be 3.41 for CHF and 3.5 for FST respectively. Elsevier Science 2003 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/114575/1/114575.pdf Tan, Ka-Kheng and Sam, Torng and Jamaludin, Hishamuddin (2003) The onset of transient convection in bottom heated porous media. International Journal of Heat and Mass Transfer, 46 (15). pp. 2857-2873. ISSN 0017-9310; eISSN: 0017-9310 https://linkinghub.elsevier.com/retrieve/pii/S0017931003000450 10.1016/S0017-9310(03)00045-0
institution Universiti Putra Malaysia
building UPM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Putra Malaysia
content_source UPM Institutional Repository
url_provider http://psasir.upm.edu.my/
language English
description The theory of transient convection in bottom heated porous media under constant heat flux (CHF) condition or fixed surface temperature (FST) condition is advanced and verified by computational fluid dynamics (CFD) simulations. The use of κ*, instead of κ m tends to artificially inflate the value of Rayleigh number by about 30%. A new transient Rayleigh number for unsteady-state heat conduction was defined to predict the onset of transient convection in porous media, which were successfully simulated. The critical transient Rayleigh number from the simulation for CHF was about 29.60, which is close to the theoretical value of 27.1 calculated by Ribando and Torrance in 1976. In the case of FST, the critical transient Rac was found to be 30.9, which is close to the theoretical value of 32.3. The critical times of onset for simulations were predicted with good accuracy. The prediction of the critical wavelengths of the emerging plumes were fair for the 2D simulations. Any experiment to verify the linear stability analysis for thermal instability must simultaneously concur in the three eigenvalue parameters, namely the Biot number, the critical wavenumber and the corresponding critical Rayleigh number, apart from the physical boundaries. The average maximum transient Nusselt number was found to be 3.41 for CHF and 3.5 for FST respectively.
format Article
author Tan, Ka-Kheng
Sam, Torng
Jamaludin, Hishamuddin
spellingShingle Tan, Ka-Kheng
Sam, Torng
Jamaludin, Hishamuddin
The onset of transient convection in bottom heated porous media
author_facet Tan, Ka-Kheng
Sam, Torng
Jamaludin, Hishamuddin
author_sort Tan, Ka-Kheng
title The onset of transient convection in bottom heated porous media
title_short The onset of transient convection in bottom heated porous media
title_full The onset of transient convection in bottom heated porous media
title_fullStr The onset of transient convection in bottom heated porous media
title_full_unstemmed The onset of transient convection in bottom heated porous media
title_sort onset of transient convection in bottom heated porous media
publisher Elsevier Science
publishDate 2003
url http://psasir.upm.edu.my/id/eprint/114575/1/114575.pdf
http://psasir.upm.edu.my/id/eprint/114575/
https://linkinghub.elsevier.com/retrieve/pii/S0017931003000450
_version_ 1825810715813871616
score 13.244413

Similar Items