Advanced

Experimental study of heat transfer control around an obstacle by using a rib

Ghorbani-Tari, Zahra LU and Sundén, Bengt LU (2016) In Heat Transfer Research 47(8). p.781-795
Abstract

This paper investigates the effect of the presence of a rib on the end-wall heat transfer of an obstacle by liquid crystal thermography. An obstacle with a rectangular cross section is placed in a rectangular channel and blocks the entire height of it (AR = 4). A rib with a square cross section is placed at two positions, i.e., in the upstream and downstream areas of the obstacle, respectively. An important parameter in dealing with the control of heat transfer around an obstacle using a rib is the spacing between them. The spacing S, normalized by the spanwise width of the obstacle, has the values 1.25 and 0.625. The effect of the rib height, normalized by the channel hydraulic diameter, e/Dh, is also investigated by... (More)

This paper investigates the effect of the presence of a rib on the end-wall heat transfer of an obstacle by liquid crystal thermography. An obstacle with a rectangular cross section is placed in a rectangular channel and blocks the entire height of it (AR = 4). A rib with a square cross section is placed at two positions, i.e., in the upstream and downstream areas of the obstacle, respectively. An important parameter in dealing with the control of heat transfer around an obstacle using a rib is the spacing between them. The spacing S, normalized by the spanwise width of the obstacle, has the values 1.25 and 0.625. The effect of the rib height, normalized by the channel hydraulic diameter, e/Dh, is also investigated by considering two values of it, i.e., 0.078 and 0.039, respectively. The results show that the local heat transfer especially in the upstream region of the obstacle is substantially modified by the upstream rib, e/Dh and S/d. The local heat transfer in the downstream region is more affected by the rib height, e/Dh. The local heat transfer in the upstream area of the obstacle is found nearly unaffected by the downstream rib regardless of the rib height e/Dh and S/d. It is found that the local heat transfer in the downstream area of the obstacle is modified differently and it is strongly affected by the rib height e/Dh and S/d. The heat transfer pattern due to the flow reattachment in the downstream area is significantly modified by the rib height e/Dh. The area influenced by the enhancement is found to be more affected by S/d. A larger enhancement area reflected a stronger impact associated with the heat transfer mechanism for e/Dh = 0.078.

(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
Control of heat transfer control, Liquid crystal thermography, Obstacle, Rib height, Rib spacing
in
Heat Transfer Research
volume
47
issue
8
pages
15 pages
publisher
Begell House
external identifiers
  • scopus:84984820704
  • wos:000391319500008
ISSN
1064-2285
DOI
10.1615/HeatTransRes.2016013378
language
English
LU publication?
yes
id
24f03b45-567c-4bea-98aa-19463b561dd2
date added to LUP
2017-02-16 14:26:32
date last changed
2017-09-18 11:33:01
@article{24f03b45-567c-4bea-98aa-19463b561dd2,
  abstract     = {<p>This paper investigates the effect of the presence of a rib on the end-wall heat transfer of an obstacle by liquid crystal thermography. An obstacle with a rectangular cross section is placed in a rectangular channel and blocks the entire height of it (AR = 4). A rib with a square cross section is placed at two positions, i.e., in the upstream and downstream areas of the obstacle, respectively. An important parameter in dealing with the control of heat transfer around an obstacle using a rib is the spacing between them. The spacing S, normalized by the spanwise width of the obstacle, has the values 1.25 and 0.625. The effect of the rib height, normalized by the channel hydraulic diameter, e/D<sub>h</sub>, is also investigated by considering two values of it, i.e., 0.078 and 0.039, respectively. The results show that the local heat transfer especially in the upstream region of the obstacle is substantially modified by the upstream rib, e/D<sub>h</sub> and S/d. The local heat transfer in the downstream region is more affected by the rib height, e/D<sub>h</sub>. The local heat transfer in the upstream area of the obstacle is found nearly unaffected by the downstream rib regardless of the rib height e/D<sub>h</sub> and S/d. It is found that the local heat transfer in the downstream area of the obstacle is modified differently and it is strongly affected by the rib height e/D<sub>h</sub> and S/d. The heat transfer pattern due to the flow reattachment in the downstream area is significantly modified by the rib height e/D<sub>h</sub>. The area influenced by the enhancement is found to be more affected by S/d. A larger enhancement area reflected a stronger impact associated with the heat transfer mechanism for e/D<sub>h</sub> = 0.078.</p>},
  author       = {Ghorbani-Tari, Zahra and Sundén, Bengt},
  issn         = {1064-2285},
  keyword      = {Control of heat transfer control,Liquid crystal thermography,Obstacle,Rib height,Rib spacing},
  language     = {eng},
  number       = {8},
  pages        = {781--795},
  publisher    = {Begell House},
  series       = {Heat Transfer Research},
  title        = {Experimental study of heat transfer control around an obstacle by using a rib},
  url          = {http://dx.doi.org/10.1615/HeatTransRes.2016013378},
  volume       = {47},
  year         = {2016},
}