Influence of duct aspect ratio on heat/mass transfer in coolant passages with rotation

Kyung Min Kim, Yun Young Kim, Dong Hyun Lee, Dong Ho Rhee, Hyung Hee Cho

Research output: Contribution to journalArticle

39 Citations (Scopus)

Abstract

The combined effects of duct aspect ratio and rotation on heat/mass transfer characteristics are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in rotating two-pass ducts with a pair of opposite rib-roughened walls. The ducts of three different aspect ratios (W/H = 0.5, 1.0, and 2.0) are employed with a fixed hydraulic diameter (D h ) of 26.7 mm. In all duct cases, the rib height-to-hydraulic diameter ratio (e/D h ) is 0.056 and the rib pitch-to-rib height (p/e) is 10. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is fixed at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for a smooth two-pass square duct using numerical simulations. The results show that Sherwood number ratios are approximately 2.5 times higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer coefficient increases as the duct aspect ratio increases. It is because the core flow is highly disturbed and accelerated in the midsections of the ribs, as the rib height-to-duct height ratio (e/H) increases. Dean vortices generated due to 180°-turn augment heat/mass transfer in the turning region and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy between leading and trailing surfaces, having higher Sherwood number on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of duct turning curvature and rotation on heat/mass transfer become less significant for the higher aspect ratio.

Original languageEnglish
Pages (from-to)357-373
Number of pages17
JournalInternational Journal of Heat and Fluid Flow
Volume28
Issue number3
DOIs
Publication statusPublished - 2007 Jun 1

Fingerprint

coolants
ducts
Coolants
Ducts
mass transfer
aspect ratio
Aspect ratio
Mass transfer
heat
hydraulics
Hydraulics
core flow
Hot Temperature
internal flow
Flow structure
coefficients
high aspect ratio
upstream
attachment
Reynolds number

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

Cite this

Kim, Kyung Min ; Kim, Yun Young ; Lee, Dong Hyun ; Rhee, Dong Ho ; Cho, Hyung Hee. / Influence of duct aspect ratio on heat/mass transfer in coolant passages with rotation. In: International Journal of Heat and Fluid Flow. 2007 ; Vol. 28, No. 3. pp. 357-373.
@article{4dc4b499bfcb47c48b90e6128dcfcfec,
title = "Influence of duct aspect ratio on heat/mass transfer in coolant passages with rotation",
abstract = "The combined effects of duct aspect ratio and rotation on heat/mass transfer characteristics are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in rotating two-pass ducts with a pair of opposite rib-roughened walls. The ducts of three different aspect ratios (W/H = 0.5, 1.0, and 2.0) are employed with a fixed hydraulic diameter (D h ) of 26.7 mm. In all duct cases, the rib height-to-hydraulic diameter ratio (e/D h ) is 0.056 and the rib pitch-to-rib height (p/e) is 10. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is fixed at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for a smooth two-pass square duct using numerical simulations. The results show that Sherwood number ratios are approximately 2.5 times higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer coefficient increases as the duct aspect ratio increases. It is because the core flow is highly disturbed and accelerated in the midsections of the ribs, as the rib height-to-duct height ratio (e/H) increases. Dean vortices generated due to 180°-turn augment heat/mass transfer in the turning region and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy between leading and trailing surfaces, having higher Sherwood number on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of duct turning curvature and rotation on heat/mass transfer become less significant for the higher aspect ratio.",
author = "Kim, {Kyung Min} and Kim, {Yun Young} and Lee, {Dong Hyun} and Rhee, {Dong Ho} and Cho, {Hyung Hee}",
year = "2007",
month = "6",
day = "1",
doi = "10.1016/j.ijheatfluidflow.2006.02.032",
language = "English",
volume = "28",
pages = "357--373",
journal = "International Journal of Heat and Fluid Flow",
issn = "0142-727X",
publisher = "Elsevier",
number = "3",

}

Influence of duct aspect ratio on heat/mass transfer in coolant passages with rotation. / Kim, Kyung Min; Kim, Yun Young; Lee, Dong Hyun; Rhee, Dong Ho; Cho, Hyung Hee.

In: International Journal of Heat and Fluid Flow, Vol. 28, No. 3, 01.06.2007, p. 357-373.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Influence of duct aspect ratio on heat/mass transfer in coolant passages with rotation

AU - Kim, Kyung Min

AU - Kim, Yun Young

AU - Lee, Dong Hyun

AU - Rhee, Dong Ho

AU - Cho, Hyung Hee

PY - 2007/6/1

Y1 - 2007/6/1

N2 - The combined effects of duct aspect ratio and rotation on heat/mass transfer characteristics are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in rotating two-pass ducts with a pair of opposite rib-roughened walls. The ducts of three different aspect ratios (W/H = 0.5, 1.0, and 2.0) are employed with a fixed hydraulic diameter (D h ) of 26.7 mm. In all duct cases, the rib height-to-hydraulic diameter ratio (e/D h ) is 0.056 and the rib pitch-to-rib height (p/e) is 10. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is fixed at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for a smooth two-pass square duct using numerical simulations. The results show that Sherwood number ratios are approximately 2.5 times higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer coefficient increases as the duct aspect ratio increases. It is because the core flow is highly disturbed and accelerated in the midsections of the ribs, as the rib height-to-duct height ratio (e/H) increases. Dean vortices generated due to 180°-turn augment heat/mass transfer in the turning region and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy between leading and trailing surfaces, having higher Sherwood number on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of duct turning curvature and rotation on heat/mass transfer become less significant for the higher aspect ratio.

AB - The combined effects of duct aspect ratio and rotation on heat/mass transfer characteristics are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in rotating two-pass ducts with a pair of opposite rib-roughened walls. The ducts of three different aspect ratios (W/H = 0.5, 1.0, and 2.0) are employed with a fixed hydraulic diameter (D h ) of 26.7 mm. In all duct cases, the rib height-to-hydraulic diameter ratio (e/D h ) is 0.056 and the rib pitch-to-rib height (p/e) is 10. The rotation number ranges from 0.0 to 0.20 while the Reynolds number is fixed at 10,000. To verify the heat/mass transfer augmentation, internal flow structures are calculated for a smooth two-pass square duct using numerical simulations. The results show that Sherwood number ratios are approximately 2.5 times higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer coefficient increases as the duct aspect ratio increases. It is because the core flow is highly disturbed and accelerated in the midsections of the ribs, as the rib height-to-duct height ratio (e/H) increases. Dean vortices generated due to 180°-turn augment heat/mass transfer in the turning region and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy between leading and trailing surfaces, having higher Sherwood number on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of duct turning curvature and rotation on heat/mass transfer become less significant for the higher aspect ratio.

UR - http://www.scopus.com/inward/record.url?scp=34247537653&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34247537653&partnerID=8YFLogxK

U2 - 10.1016/j.ijheatfluidflow.2006.02.032

DO - 10.1016/j.ijheatfluidflow.2006.02.032

M3 - Article

VL - 28

SP - 357

EP - 373

JO - International Journal of Heat and Fluid Flow

JF - International Journal of Heat and Fluid Flow

SN - 0142-727X

IS - 3

ER -