An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs

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

Research output: Contribution to conferencePaper

7 Citations (Scopus)

Abstract

The effects of duct aspect ratio on heat/mass transfer are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in a rotating two-pass duct with 90°-rib turbulators. The duct has three aspect ratios ( W/H=0.5, 1.0, and 2.0) with a fixed hydraulic diameter (Dh) of 26.7 mm. 90°-rib turbulators are installed on the leading and trailing sides symmetrically. The rib height-to-hydraulic diameter ratio (e/Dh) is 0.056, and the rib height remains constant in all duct cases. The Reynolds number based on the hydraulic diameter is fixed to 10,000 and the rotation number ranges from 0.0 to 0.20. The results show that Sherwood number ratios are 2.5 tunes higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer in the first pass is more enhanced in higher aspect ratio duct because the rib height-to-duct height ratio increases, which results in more turbulated and accelerated flow in the midsections of the ribs. Dean vortices augment heat/mass transfer in the turn and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy, having higher Sherwood number ratios on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of turning region and rotation on heat/mass transfer become less significant with the increment of duct aspect ratio.

Original languageEnglish
Pages483-492
Number of pages10
Publication statusPublished - 2004 Dec 22
Event2004 ASME Turbo Expo - Vienna, Austria
Duration: 2004 Jun 142004 Jun 17

Other

Other2004 ASME Turbo Expo
CountryAustria
CityVienna
Period04/6/1404/6/17

Fingerprint

Ducts
Aspect ratio
Mass transfer
Hydraulics
Hot Temperature
Vortex flow
Reynolds number
Pipe
Experiments

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Cite this

Kim, K. M., Kim, Y. Y., Rhee, D. H., & Cho, H. H. (2004). An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs. 483-492. Paper presented at 2004 ASME Turbo Expo, Vienna, Austria.
Kim, Kyung Min ; Kim, Yun Young ; Rhee, Dong Ho ; Cho, Hyung Hee. / An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs. Paper presented at 2004 ASME Turbo Expo, Vienna, Austria.10 p.
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abstract = "The effects of duct aspect ratio on heat/mass transfer are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in a rotating two-pass duct with 90°-rib turbulators. The duct has three aspect ratios ( W/H=0.5, 1.0, and 2.0) with a fixed hydraulic diameter (Dh) of 26.7 mm. 90°-rib turbulators are installed on the leading and trailing sides symmetrically. The rib height-to-hydraulic diameter ratio (e/Dh) is 0.056, and the rib height remains constant in all duct cases. The Reynolds number based on the hydraulic diameter is fixed to 10,000 and the rotation number ranges from 0.0 to 0.20. The results show that Sherwood number ratios are 2.5 tunes higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer in the first pass is more enhanced in higher aspect ratio duct because the rib height-to-duct height ratio increases, which results in more turbulated and accelerated flow in the midsections of the ribs. Dean vortices augment heat/mass transfer in the turn and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy, having higher Sherwood number ratios on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of turning region and rotation on heat/mass transfer become less significant with the increment of duct aspect ratio.",
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Kim, KM, Kim, YY, Rhee, DH & Cho, HH 2004, 'An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs', Paper presented at 2004 ASME Turbo Expo, Vienna, Austria, 04/6/14 - 04/6/17 pp. 483-492.

An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs. / Kim, Kyung Min; Kim, Yun Young; Rhee, Dong Ho; Cho, Hyung Hee.

2004. 483-492 Paper presented at 2004 ASME Turbo Expo, Vienna, Austria.

Research output: Contribution to conferencePaper

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N2 - The effects of duct aspect ratio on heat/mass transfer are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in a rotating two-pass duct with 90°-rib turbulators. The duct has three aspect ratios ( W/H=0.5, 1.0, and 2.0) with a fixed hydraulic diameter (Dh) of 26.7 mm. 90°-rib turbulators are installed on the leading and trailing sides symmetrically. The rib height-to-hydraulic diameter ratio (e/Dh) is 0.056, and the rib height remains constant in all duct cases. The Reynolds number based on the hydraulic diameter is fixed to 10,000 and the rotation number ranges from 0.0 to 0.20. The results show that Sherwood number ratios are 2.5 tunes higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer in the first pass is more enhanced in higher aspect ratio duct because the rib height-to-duct height ratio increases, which results in more turbulated and accelerated flow in the midsections of the ribs. Dean vortices augment heat/mass transfer in the turn and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy, having higher Sherwood number ratios on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of turning region and rotation on heat/mass transfer become less significant with the increment of duct aspect ratio.

AB - The effects of duct aspect ratio on heat/mass transfer are investigated. Mass transfer experiments are conducted to obtain detailed local heat/mass transfer coefficients on the leading and trailing surfaces in a rotating two-pass duct with 90°-rib turbulators. The duct has three aspect ratios ( W/H=0.5, 1.0, and 2.0) with a fixed hydraulic diameter (Dh) of 26.7 mm. 90°-rib turbulators are installed on the leading and trailing sides symmetrically. The rib height-to-hydraulic diameter ratio (e/Dh) is 0.056, and the rib height remains constant in all duct cases. The Reynolds number based on the hydraulic diameter is fixed to 10,000 and the rotation number ranges from 0.0 to 0.20. The results show that Sherwood number ratios are 2.5 tunes higher than the fully developed value in a stationary smooth pipe due to the flow reattachment near ribbed surfaces. The overall heat/mass transfer in the first pass is more enhanced in higher aspect ratio duct because the rib height-to-duct height ratio increases, which results in more turbulated and accelerated flow in the midsections of the ribs. Dean vortices augment heat/mass transfer in the turn and in the upstream region of the second pass. The rotation of duct produces heat/mass transfer discrepancy, having higher Sherwood number ratios on the trailing surface in the first pass and on the leading surface in the second pass. However, the effects of turning region and rotation on heat/mass transfer become less significant with the increment of duct aspect ratio.

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Kim KM, Kim YY, Rhee DH, Cho HH. An investigation of duct aspect ratio effects on heat/mass transfer in a rotating duct with 90° ribs. 2004. Paper presented at 2004 ASME Turbo Expo, Vienna, Austria.