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Analysis of heat transfer and fluid flow of a slot jet impinging on a confined concave surface with various curvature and small jet to target spacing

Qiu, Dandan ; Luo, Lei ; Wang, Songtao ; Sunden, Bengt Ake LU and Zhang, Xinhong (2019) In International Journal of Numerical Methods for Heat and Fluid Flow
Abstract

Purpose: This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing. Design/methodology/approach: Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed. Findings: It is found that an obvious backflow occurs near the upper wall. Both the local and averaged... (More)

Purpose: This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing. Design/methodology/approach: Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed. Findings: It is found that an obvious backflow occurs near the upper wall. Both the local and averaged Nusselt numbers considered in the defined region respond positively to the Rej. The surface curvature plays a positive role in increasing the averaged Nusselt number for smaller surface curvature (4-15) but affects little as the surface curvature is large enough (> 15). The thermal performance is larger for smaller surface curvature and changes little as the surface curvature is larger than 15. The jet to target spacing shows a negative effect in heat transfer enhancement and thermal performance. Originality/value: The surface curvature effects are conducted by verifying the concave surface with constant jet size. The flow characteristics are first obtained for the confined impingement cases. Then confined and unconfined slot jet impingements are compared. An ineffective point for surface curvature effects on heat transfer and thermal performance is obtained.

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author
organization
publishing date
type
Contribution to journal
publication status
epub
subject
keywords
Flow dynamics, Heat transfer, Jet to target spacing, Reynolds number, Slot jet impingement, Surface curvature
in
International Journal of Numerical Methods for Heat and Fluid Flow
publisher
Emerald Group Publishing Limited
external identifiers
  • scopus:85070305242
ISSN
0961-5539
DOI
10.1108/HFF-07-2018-0354
language
English
LU publication?
yes
id
3be8767a-30b8-4cc5-9646-0866ecb9cad4
date added to LUP
2019-08-27 08:54:47
date last changed
2019-11-25 09:33:44
@article{3be8767a-30b8-4cc5-9646-0866ecb9cad4,
  abstract     = {<p>Purpose: This study aims to focus on the surface curvature, jet to target spacing and jet Reynolds number effects on the heat transfer and fluid flow characteristics of a slot jet impinging on a confined concave target surface at constant jet to target spacing. Design/methodology/approach: Numerical simulations are used in this research. Jet to target spacing, H/B is varying from 1.0 to 2.2, B is the slot width. The jet Reynolds number, Rej, varies from 8,000 to 40,000, and the surface curvature, R2/B, varies from 4 to 20. Results of the target surface heat transfer, flow parameters and fluid flow in the concave channel are performed. Findings: It is found that an obvious backflow occurs near the upper wall. Both the local and averaged Nusselt numbers considered in the defined region respond positively to the Rej. The surface curvature plays a positive role in increasing the averaged Nusselt number for smaller surface curvature (4-15) but affects little as the surface curvature is large enough (&gt; 15). The thermal performance is larger for smaller surface curvature and changes little as the surface curvature is larger than 15. The jet to target spacing shows a negative effect in heat transfer enhancement and thermal performance. Originality/value: The surface curvature effects are conducted by verifying the concave surface with constant jet size. The flow characteristics are first obtained for the confined impingement cases. Then confined and unconfined slot jet impingements are compared. An ineffective point for surface curvature effects on heat transfer and thermal performance is obtained.</p>},
  author       = {Qiu, Dandan and Luo, Lei and Wang, Songtao and Sunden, Bengt Ake and Zhang, Xinhong},
  issn         = {0961-5539},
  language     = {eng},
  month        = {07},
  publisher    = {Emerald Group Publishing Limited},
  series       = {International Journal of Numerical Methods for Heat and Fluid Flow},
  title        = {Analysis of heat transfer and fluid flow of a slot jet impinging on a confined concave surface with various curvature and small jet to target spacing},
  url          = {http://dx.doi.org/10.1108/HFF-07-2018-0354},
  doi          = {10.1108/HFF-07-2018-0354},
  year         = {2019},
}