Advanced

Effect of aspect ratio on entropy generation in a rectangular cavity with differentially heated vertical walls

Ilis, Gamze Gediz; Mobedi, Moghtada and Sundén, Bengt LU (2008) In International Communications in Heat and Mass Transfer 35(6). p.696-703
Abstract
In the present study, entropy generation in rectangular cavities with the same area but different aspect ratios is numerically investigated. The vertical walls of the cavities are at different constant temperatures while the horizontal walls are adiabatic. Heat transfer between vertical walls occurs by laminar natural convection. Based on the obtained dimensionless velocity and temperature values, the distributions of local entropy generation due to heat transfer and fluid friction, the local Bejan number and local entropy generation number are determined and related maps are plotted. The variation of the total entropy generation and average Bejan number for the whole cavity volume at different aspect ratios for different values of the... (More)
In the present study, entropy generation in rectangular cavities with the same area but different aspect ratios is numerically investigated. The vertical walls of the cavities are at different constant temperatures while the horizontal walls are adiabatic. Heat transfer between vertical walls occurs by laminar natural convection. Based on the obtained dimensionless velocity and temperature values, the distributions of local entropy generation due to heat transfer and fluid friction, the local Bejan number and local entropy generation number are determined and related maps are plotted. The variation of the total entropy generation and average Bejan number for the whole cavity volume at different aspect ratios for different values of the Rayleigh number and irreversibility distribution ratio are also evaluated. It is found that for a cavity with high value of Rayleigh number (i.e., Ra = 10(5)), the total entropy generation due to fluid friction and total entropy generation number increase with increasing aspect ratio, attain a maximum and then decrease. The present results are compared with reported solutions and excellent agreement is observed. The study is performed for 10(2) < Ra < 10(5), 10(-4) < 0 < 10(-2), and Pr = 0.7. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
natural convection, entropy generation, Bejan number
in
International Communications in Heat and Mass Transfer
volume
35
issue
6
pages
696 - 703
publisher
Elsevier
external identifiers
  • wos:000256704500002
  • scopus:43449100318
ISSN
0735-1933
DOI
10.1016/j.icheatmasstransfer.2008.02.002
language
English
LU publication?
yes
id
32ae0e20-80db-4d5e-b066-e08847856e5a (old id 1191396)
date added to LUP
2008-09-08 14:51:30
date last changed
2017-09-17 05:04:27
@article{32ae0e20-80db-4d5e-b066-e08847856e5a,
  abstract     = {In the present study, entropy generation in rectangular cavities with the same area but different aspect ratios is numerically investigated. The vertical walls of the cavities are at different constant temperatures while the horizontal walls are adiabatic. Heat transfer between vertical walls occurs by laminar natural convection. Based on the obtained dimensionless velocity and temperature values, the distributions of local entropy generation due to heat transfer and fluid friction, the local Bejan number and local entropy generation number are determined and related maps are plotted. The variation of the total entropy generation and average Bejan number for the whole cavity volume at different aspect ratios for different values of the Rayleigh number and irreversibility distribution ratio are also evaluated. It is found that for a cavity with high value of Rayleigh number (i.e., Ra = 10(5)), the total entropy generation due to fluid friction and total entropy generation number increase with increasing aspect ratio, attain a maximum and then decrease. The present results are compared with reported solutions and excellent agreement is observed. The study is performed for 10(2) &lt; Ra &lt; 10(5), 10(-4) &lt; 0 &lt; 10(-2), and Pr = 0.7.},
  author       = {Ilis, Gamze Gediz and Mobedi, Moghtada and Sundén, Bengt},
  issn         = {0735-1933},
  keyword      = {natural convection,entropy generation,Bejan number},
  language     = {eng},
  number       = {6},
  pages        = {696--703},
  publisher    = {Elsevier},
  series       = {International Communications in Heat and Mass Transfer},
  title        = {Effect of aspect ratio on entropy generation in a rectangular cavity with differentially heated vertical walls},
  url          = {http://dx.doi.org/10.1016/j.icheatmasstransfer.2008.02.002},
  volume       = {35},
  year         = {2008},
}