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Heat Transfer and Secondary Flow Characteristics in a Horizontally Round Pipe for Cooling a Scramjet Combustor by Supercritical n-Decane

Li, Yong LU orcid ; Chen, Youqian ; Xie, Gongnan LU and Sunden, Bengt LU (2021) In Journal of Energy Resources Technology 143(2).
Abstract

To figure out the abnormal flow characteristics and thermal performance of supercritical fluids, some detailed information of supercritical pressure n-decane flowing in a horizontally round pipe is studied in terms of secondary flow induced by the huge density change or buoyancy force. According to an evaluation of turbulence models, the shear stress transport k-ω is suitable to execute the case of horizontal flow. It is observed that the temperature distributions between the upper wall region and the lower wall region are asymmetric and the location of the maximum buoyancy force coincided with the position of Tpc (pseudo-critical temperature). The generation of a rotating flow arising from the heated wall determines the occurrence of... (More)

To figure out the abnormal flow characteristics and thermal performance of supercritical fluids, some detailed information of supercritical pressure n-decane flowing in a horizontally round pipe is studied in terms of secondary flow induced by the huge density change or buoyancy force. According to an evaluation of turbulence models, the shear stress transport k-ω is suitable to execute the case of horizontal flow. It is observed that the temperature distributions between the upper wall region and the lower wall region are asymmetric and the location of the maximum buoyancy force coincided with the position of Tpc (pseudo-critical temperature). The generation of a rotating flow arising from the heated wall determines the occurrence of heat transfer deterioration (HTD). In the boom stage of the HTD phenomenon, a dead zone that is close to the upper wall was formed due to the influence of vortices. In contrast, the maximum buoyancy force is located in the core flow zone and it forces the fluid in the mainstream to participate in the cooling process of the heated wall. In addition, the dead zone in the vicinity of the upper wall is broken. This is the main reason why heat transfer deterioration could be inhibited effectively.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
buoyancy force, energy conversion/systems, heat energy generation/ storage/transfer, heat transfer deterioration, horizontally round pipe, secondary flow, Supercritical n-decane
in
Journal of Energy Resources Technology
volume
143
issue
2
article number
022105
publisher
American Society Of Mechanical Engineers (ASME)
external identifiers
  • scopus:85092049416
ISSN
0195-0738
DOI
10.1115/1.4047760
language
English
LU publication?
yes
id
08409d9c-a5f4-4362-8728-ad1be8e3eade
date added to LUP
2020-10-26 10:50:13
date last changed
2022-04-19 01:21:33
@article{08409d9c-a5f4-4362-8728-ad1be8e3eade,
  abstract     = {{<p>To figure out the abnormal flow characteristics and thermal performance of supercritical fluids, some detailed information of supercritical pressure n-decane flowing in a horizontally round pipe is studied in terms of secondary flow induced by the huge density change or buoyancy force. According to an evaluation of turbulence models, the shear stress transport k-ω is suitable to execute the case of horizontal flow. It is observed that the temperature distributions between the upper wall region and the lower wall region are asymmetric and the location of the maximum buoyancy force coincided with the position of Tpc (pseudo-critical temperature). The generation of a rotating flow arising from the heated wall determines the occurrence of heat transfer deterioration (HTD). In the boom stage of the HTD phenomenon, a dead zone that is close to the upper wall was formed due to the influence of vortices. In contrast, the maximum buoyancy force is located in the core flow zone and it forces the fluid in the mainstream to participate in the cooling process of the heated wall. In addition, the dead zone in the vicinity of the upper wall is broken. This is the main reason why heat transfer deterioration could be inhibited effectively. </p>}},
  author       = {{Li, Yong and Chen, Youqian and Xie, Gongnan and Sunden, Bengt}},
  issn         = {{0195-0738}},
  keywords     = {{buoyancy force; energy conversion/systems; heat energy generation/ storage/transfer; heat transfer deterioration; horizontally round pipe; secondary flow; Supercritical n-decane}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{2}},
  publisher    = {{American Society Of Mechanical Engineers (ASME)}},
  series       = {{Journal of Energy Resources Technology}},
  title        = {{Heat Transfer and Secondary Flow Characteristics in a Horizontally Round Pipe for Cooling a Scramjet Combustor by Supercritical n-Decane}},
  url          = {{http://dx.doi.org/10.1115/1.4047760}},
  doi          = {{10.1115/1.4047760}},
  volume       = {{143}},
  year         = {{2021}},
}