Entropy generation for unsteady natural convection and thermal radiation inside a porous enclosure. (16th July 2013)

• Record Type: Journal Article
• Authors: Jbara, Abdesslem; Slimi, Khalifa; Mhimid, Abdallah
• Is Part Of: International journal of exergy. Volume 12:Number 4(2013)
• Page Start: 522
• Page End: 551
• Publication Date: 2013-07-16
• Subjects: entropy generation -- porous enclosures -- thermal radiation -- unsteady natural convection -- finite volume method -- fluid flow -- heat transfer -- radiative transfer irreversibilities; Exergy -- Periodicals; 621.402105
• Languages: English
• ISSNs: 1742-8297

Abstract

Entropy generation problem for unsteady natural convection and thermal radiation in a vertical porous enclosure, submitted to a uniform hot walls temperature and filled with a fluid saturated porous medium, has been performed. A time–space variations study is presented for fluid flow, heat transfer and radiative transfer irreversibilities, local entropy generation Sgen and modified Bejan number Bem . A sensitivity study shows that Bem increases, particularly near the boundaries, due to an increase in N or Br values and it decreases as τD or R values increase. For the cases of ε and ω, an inversion phenomenon is observed. Furthermore, Sgen and the total entropy generation Egen values rise when there is an increase in ε, τD, R or Br values. In opposition, Sgen and Egen values decrease with the increase of ω or N values.