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Solar air heater performance enhancement with differently shaped miniature combined with dimple shaped roughness : CFD and experimental analysis

Arya, Navneet ; Goel, Varun and Sunden, Bengt LU (2023) In Solar Energy 250. p.33-50
Abstract

A numerical study was carried out in a solar air heater (SAH) using different shapes of miniature (V, arc and transverse broken-miniature) combined with dimples on an absorber panel to improve heat transfer. For an experimental and simulation study using ANSYS (Fluent), a dimple with a V-miniature rib was fabricated on a plate (absorber) as a roughness element. By providing the angle of attack (α), relative long way (RLL) length (l/d), relative height (roughness) and relative wire lengths (w/Dh) ranging from 45 to 75°, 15–25, 0.024–0.036 and 0.14–0.21 respectively. The thermohydraulic performance (THP) factor of the proposed roughness was also investigated at Reynolds numbers (Re) ranging from 5000 to 20000. Results of... (More)

A numerical study was carried out in a solar air heater (SAH) using different shapes of miniature (V, arc and transverse broken-miniature) combined with dimples on an absorber panel to improve heat transfer. For an experimental and simulation study using ANSYS (Fluent), a dimple with a V-miniature rib was fabricated on a plate (absorber) as a roughness element. By providing the angle of attack (α), relative long way (RLL) length (l/d), relative height (roughness) and relative wire lengths (w/Dh) ranging from 45 to 75°, 15–25, 0.024–0.036 and 0.14–0.21 respectively. The thermohydraulic performance (THP) factor of the proposed roughness was also investigated at Reynolds numbers (Re) ranging from 5000 to 20000. Results of average Nusselt number, turbulent kinetic energy (TKE), fluid flow characteristics and temperature are included to analyse the comparative merits of each dimple with miniature arrangements. The results revealed that among dimples with different miniatures, 90° transverse broken-miniature with dimple shows best thermohydraulic performance at Re below 10,000 while a dimple with V-miniature at an angle of attack (α) 45° shows the highest thermohydraulic performance at Re above 8750. It was found that THP achieved a maximum value of 1.63 at α = 45°, l/d = 20 and w/Dh = 0.18 at Reynolds number 12,500 for the dimple with a V-miniature rib.

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author
; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
CFD, Dimple with different miniature, Solar air heater, Thermohydraulic performance
in
Solar Energy
volume
250
pages
18 pages
publisher
Elsevier
external identifiers
  • scopus:85144846059
ISSN
0038-092X
DOI
10.1016/j.solener.2022.12.024
language
English
LU publication?
yes
id
61f0fb93-ff30-4564-8462-d13c518222c4
date added to LUP
2023-02-03 08:11:33
date last changed
2023-11-21 06:37:23
@article{61f0fb93-ff30-4564-8462-d13c518222c4,
  abstract     = {{<p>A numerical study was carried out in a solar air heater (SAH) using different shapes of miniature (V, arc and transverse broken-miniature) combined with dimples on an absorber panel to improve heat transfer. For an experimental and simulation study using ANSYS (Fluent), a dimple with a V-miniature rib was fabricated on a plate (absorber) as a roughness element. By providing the angle of attack (α), relative long way (RLL) length (l/d), relative height (roughness) and relative wire lengths (w/D<sub>h</sub>) ranging from 45 to 75°, 15–25, 0.024–0.036 and 0.14–0.21 respectively. The thermohydraulic performance (THP) factor of the proposed roughness was also investigated at Reynolds numbers (Re) ranging from 5000 to 20000. Results of average Nusselt number, turbulent kinetic energy (TKE), fluid flow characteristics and temperature are included to analyse the comparative merits of each dimple with miniature arrangements. The results revealed that among dimples with different miniatures, 90° transverse broken-miniature with dimple shows best thermohydraulic performance at Re below 10,000 while a dimple with V-miniature at an angle of attack (α) 45° shows the highest thermohydraulic performance at Re above 8750. It was found that THP achieved a maximum value of 1.63 at α = 45°, l/d = 20 and w/D<sub>h</sub> = 0.18 at Reynolds number 12,500 for the dimple with a V-miniature rib.</p>}},
  author       = {{Arya, Navneet and Goel, Varun and Sunden, Bengt}},
  issn         = {{0038-092X}},
  keywords     = {{CFD; Dimple with different miniature; Solar air heater; Thermohydraulic performance}},
  language     = {{eng}},
  month        = {{01}},
  pages        = {{33--50}},
  publisher    = {{Elsevier}},
  series       = {{Solar Energy}},
  title        = {{Solar air heater performance enhancement with differently shaped miniature combined with dimple shaped roughness : CFD and experimental analysis}},
  url          = {{http://dx.doi.org/10.1016/j.solener.2022.12.024}},
  doi          = {{10.1016/j.solener.2022.12.024}},
  volume       = {{250}},
  year         = {{2023}},
}