Heat Transfer and Secondary Flow Characteristics in a Horizontally Round Pipe for Cooling a Scramjet Combustor by Supercritical n-Decane
(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
- Li, Yong LU ; Chen, Youqian ; Xie, Gongnan LU and Sunden, Bengt LU
- organization
- publishing date
- 2021-02-01
- 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}}, }