Heat transfer of air/water mist flow in a single-side heated vertical duct was experimentally investigated. The mist flow was produced by introducing fine dispersed water droplets into the air stream, and the water–air mass flow ratios were up to 15%. The Reynolds numbers of the air flow were 7900, 16,000, and 24,000. The rib spacing-to-height ratios were 10 and 20 in the current study. Mist flow cooling achieved higher heat transfer rates mainly because of the droplet deposition and liquid film formation on the heated surface. The heat transfer enhancement on the smooth surface by the mist flow was 4–6 times as high as the air flow. On the ribbed surface, a smaller rib spacing of 10 was preferred for air cooling, since the heat transfer enhancement by the flow reattachment was better utilized. However, the rib-induced secondary flow blew away the liquid films on the surface, and the heat transfer enhancement was degraded near the reattachment region for the mist cooling. A larger rib spacing-to-height ratio of 20 thus achieved higher heat transfer because of the liquid film formation beyond the reattachment region. The heat transfer enhancement on the ribbed surface using mist flow was 2.5–3.5 times as high as the air flow. The friction factor of the mist flow was two times as high as the air flow in the ribbed duct.
Issue Section:
Research Papers
Keywords:
Experimental,
Forced convection,
Gas turbine heat transfer,
Heat transfer enhancement,
Measurement techniques
Topics:
Cooling,
Ducts,
Flow (Dynamics),
Heat transfer,
Water,
Friction,
Drops,
Liquid films,
Reynolds number
References
1.
Heyt
, J. W.
, and Larsen
, P. S.
, 1970
, “Heat Transfer to Binary Mist Flow
,” Int. J. Heat Mass Transfer
, 14
(9
), pp. 1395
–1405
.2.
Toda
, S.
, 1972
, “A Study of Mist-Cooling (1st Report: Investigation of Mist Cooling)
,” Heat Transfer Jpn. Res.
, 1
(3
), pp. 39
–50
.3.
Toda
, S.
, 1974
, “A Study of Mist Cooling: Theory of Mist Cooling and Its Fundamental Experiments
,” Heat Transfer Jpn. Res.
, 3
(1
), pp. 1
–44
.4.
Aihara
, T.
, Taga
, M.
, and Haraguchi
, T.
, 1979
, “Heat Transfer From a Uniform Heat Flux Wedge in Air-Water Mist Flows
,” Int. J. Heat Mass Transfer
, 22
(1
), pp. 51
–60
.5.
Trela
, M.
, 1981
, “An Approximation Calculation of Heat Transfer During Flow of an Air-Water Mist Flow Along a Heated Flat Plate
,” Int. J. Heat Mass Transfer
, 24
(4
), pp. 749
–755
.6.
Fu
, W. S.
, and Wu
, R. M.
, 1988
, “Heat Transfer From an Isothermal Wedge in an Air-Water Mist Flow
,” Int. J. Heat Mass Transfer
, 31
(6
), pp. 1157
–1195
.7.
Fu
, W. S.
, and Yang
, G. C.
, 1989
, “Influence of Droplets' Trajectories and Size Distribution on Heat Transfer From a Wedge in an Air-Water Mist Flow
,” Numer. Heat Transfer, Part A
, 16
(2
), pp. 155
–174
.8.
Aihara
, T.
, Fu
, W. S.
, and Suzuki
, Y.
, 1990
, “Numerical Analysis of Heat and Mass Transfer From Horizontal Cylinders in Downward Flow of Air-Water Mist
,” ASME J. Heat Transfer
, 112
(2
), pp. 472
–478
.9.
Aihara
, T.
, 1990
, “Augmentation of Convective Heat Transfer by Gas-Liquid Mist
,” International Heat Transfer Conference
, Jerusalem, Israel, Aug. 19–24, Vol. 1
, pp. 445
–461
.10.
Nakayama
, W.
, Kuwahara
, H.
, and Hirasawa
, S.
, 1988
, “Heat Transfer From Tubes Banks to Air/Water Mist Flow
,” Int. J. Heat Mass Transfer
, 31
(2
), pp. 449
–460
.11.
Hayashi
, Y.
, Takimoto
, A.
, Matsuda
, O.
, and Kitagawa
, T.
, 1990
, “Study on Mist Cooling for Heat Exchanger
,” JSME Int. J.
, 33
(2
), pp. 333
–339
.12.
Hayashi
, Y.
, Takimoto
, A.
, and Matsuda
, O.
, 1991
, “Heat Transfer From Tubes in Mist Flows
,” Exp. Heat Transfer
, 4
(4
), pp. 291
–308
.13.
Lee
, S. L.
, Yang
, Z. H.
, and Hsyua
, Y.
, 1994
, “Cooling of a Heated Surface by Mist Flow
,” ASME J. Heat Transfer
, 116
(1
), pp. 167
–172
.14.
Lee
, S. L.
, and Srinivasan
, J.
, 1982
, “A Laser Doppler Velocimetry Technique for In-Situ Local Measurement of Dilute Two-Phase Suspension Flow
,” Engineering Application of Laser Velocimetry Symposium
, Phoenix, AZ, Nov. 14–19, pp. 117
–125
.15.
Han
, J. C.
, and Park
, J. S.
, 1988
, “Developing Heat Transfer in Rectangular Channels With Rib Turbulators
,” Int. J. Heat Mass Transfer
, 31
(1
), pp. 183
–195
.16.
Liou
, T. M.
, and Hwang
, J. J.
, 1993
, “Effect of Ridge Shapes on Turbulent Heat Transfer and Friction in a Rectangular Channel
,” Int. J. Heat Mass Transfer
, 36
(4
), pp. 931
–940
.17.
Taslim
, M. E.
, and Spring
, S. D.
, 1994
, “Effects of Turbulator Profile and Spacing on Heat Transfer and Friction in a Channel
,” AIAA J. Thermophys. Heat Transfer
, 8
(3
), pp. 555
–562
.18.
Liu
, Y. H.
, and Lai
, S. Y.
, 2012
, “Heat Transfer Augmentation in Rotating Triangular Channels With Discrete and V-Shaped Ribs
,” AIAA J. Thermophys. Heat Transfer
, 26
(4
), pp. 603
–611
.19.
Dhanasekaran
, T. S.
, and Wang
, T.
, 2013
, “Computational Analysis of Mist/Air Cooling in a Two-Pass Rectangular Rotating Channel With 45-deg Angled Rib Turbulator
,” Int. J. Heat Mass Transfer
, 61
, pp. 554
–564
.20.
Elwekeel
, F. N. M.
, Zheng
, Q.
, and Abdala
, A. M. M.
, 2014
, “Numerical Study of Turbulent Flow Through Rib-Roughened Channels With Mist Injection
,” ASME
Paper No. GT2014-25408.21.
Zeng
, J.
, Gao
, T.
, Li
, J.
, Zhu
, J.
, and Fei
, J.
, 2016
, “Numerical Investigation on Flow and Heat Transfer Characteristics of Steam and Mist/Steam in Internal Cooling Channels With Different Rib Angles
,” ASME
Paper No. GT2016-56812.22.
Pan
, G.
, Shakal
, J.
, Lai
, W.
, Calabria
, R.
, and Massoli
, P.
, 2006
, “Spray Features Investigated by GSV: A New Planar Laser Technique
,” Tenth International Conference on Liquid Atomization and Spray Systems
(ICLASS
), Kyoto, Japan, Aug. 27–Sept. 1, Paper No. 06-283.23.
Moffat
, R. J.
, 1988
, “Describing the Uncertainties in Experimental Results
,” Exp. Therm. Fluid Sci.
, 1
(1
), pp. 3
–17
.24.
Webb
, R. L.
, Eckert
, E. R. G.
, and Goldstein
, R. J.
, 1971
, “Heat Transfer and Friction in Tubes With Repeated-Rib Roughness
,” Int. J. Heat Mass Transfer
, 14
(4
), pp. 601
–617
.25.
Ekkad
, S. V.
, and Han
, J. C.
, 1997
, “Detailed Heat Transfer Distributions in Two-Pass Square Channels With Rib Turbulators
,” Int. J. Heat Mass Transfer
, 40
(11
), pp. 2525
–2537
.26.
Mayo
, I.
, Arts
, T.
, EI-Habib
, A.
, and Parres
, B.
, 2015
, “Two-Dimensional Heat Transfer Distribution of a Rotating Ribbed Channel at Different Reynolds Numbers
,” ASME J. Turbomach.
, 137
(3
), pp. 1
–11
.27.
Šefko
, Š.
, and Edin
, B.
, 2015
, “Analysis of Droplet Deposition in a Vertical Air-Water Dispersed Flow
,” Procedia Eng.
, 100
, pp. 105
–114
.28.
Ishii
, M.
, and Mishima
, K.
, 1989
, “Droplet Entrainment Correlation in Annular Two-Phase Flow
,” Int. J. Heat Mass Transfer
, 32
(10
), pp. 1835
–1846
.29.
Novak
, V.
, Sadowski
, D. L.
, Schoonover
, K. G.
, Abdel-Khalik
, S. I.
, and Ghiaasiaan
, S. M.
, 2008
, “Heat Transfer in Two-Component Internal Mist Cooling—Part I: Experimental Investigation
,” Nucl. Eng. Des.
, 238
(9
), pp. 2341
–2350
.30.
Chandra
, P. R.
, and Cook
, M. M.
, 1994
, “Effect of the Number of Channel Ribbed Walls on Heat Transfer and Friction Characteristics of Turbulent Flows
,” Sixth AIAA/ASME Thermophysics and Heat Transfer Conference
, Colorado Springs, CO, June 20–23, pp. 201
–209
.Copyright © 2017 by ASME
You do not currently have access to this content.
