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Turbulence structure and mass transfer across a sheared air–water interface in wind-driven turbulence

Published online by Cambridge University Press:  26 April 2006

Satoru Komori ,
Ryuichi Nagaosa  and
Yasuhiro Murakami
Satoru Komori
Affiliation:
Department of Chemical Engineering, Kyushu University, Hakozaki, Fukuoka 812, Japan
Ryuichi Nagaosa
Affiliation:
Department of Chemical Engineering, Kyushu University, Hakozaki, Fukuoka 812, Japan
Yasuhiro Murakami
Affiliation:
Department of Chemical Engineering, Kyushu University, Hakozaki, Fukuoka 812, Japan
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Abstract

The mass transfer mechanism across a sheared air–water interface without bubble entrainment due to wave breaking was experimentally investigated in terms of the turbulence structure of the organized motions in the interfacial region in a wind-wave tank. The transfer velocity of the carbon dioxide (CO2) on the water side was measured through reaeration experiments of CO2, and the fluid velocities in the air and water flows were measured using both a hot-wire anemometer and a laser-Doppler velocimeter. The results show that the mass transfer across a sheared air–water interface is more intensively promoted in wind shear, compared to an unsheared interface. However, the effect of the wind shear on the mass transfer tends to saturate in the high-shear region in the present wind-wave tank, where the increasing rate of mass transfer velocity with the wind shear decreases rapidly. The effect of the wind shear on the mass transfer can be well explained on the basis of the turbulence structure near the air–water interface. That is, surface-renewal eddies are induced on the water side through the high wind shear on the air–water interface by the strong organized motion generated in the air flow above the interface, and the renewal eddies control the mass transfer across a sheared interface. The mass transfer velocity is correlated with the frequency of the appearance of the surface-renewal eddies, as it is in open-channel flows with unsheared interfaces, and it increases approximately in proportion to the root of the surface-renewal frequency. The surface-renewal frequency increases with increasing the wind shear, but for high shear the rate of increase slows. This results in the saturated effect of the wind shear on the mass transfer in the high-shear region in the present wind-wave tank. The mass transfer velocity can be well estimated by the surface-renewal eddy-cell model based on the concept of the time fraction when the surface renewal occurs.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 249 , April 1993 , pp. 161 - 183
Copyright
© 1993 Cambridge University Press

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References

Alfredsson, P. H. & Johansson, A. V. 1984 On the detection of turbulence-generating events. J. Fluid Mech. 139, 325– 345.Google Scholar
Asher, W. E. & Pankow, J. F. 1991 Prediction of gas/water mass transport coefficient by a surface-renewal model. Environ. Sci. Technol. 25, 1294– 1300.Google Scholar
Banerjee, S. 1990 Turbulence structure and transport mechanism at interfaces. In Proc. Ninth Intl Heat Transfer Conf. (ed. G. Hetsroni), vol. 1, pp. 395– 418. Hemisphere.
Banerjee, S. 1991 Turbulence/interface interactions. In Phase-Interface Phenomena in Multiphase Flow (ed. G. F. Hewitt, F. Mayinger & J. R. Riznic), pp. 3– 19. Hemisphere.
Bendat, J. S. & Piersol, A. G. 1971 RANDAM DATA: Analysis and Measurement Procedures. John Wiley & Sons.
Blackwelder, R. F. & Kaplan, R. E. 1976 On the wall structure of the turbulent boundary layer. J. Fluid Mech. 76, 89– 112.Google Scholar
Broecker, W. S. & Peng, T. H. 1974 Gas exchange rates between air and sea. Tellus 26, 21– 35.Google Scholar
Broecker, H. C., Petermann, J. & Siems, W. 1978 The influence of wind on CO2-exchange in a wind-wave tunnel, including the effects of monolayers. J. Mar. Res. 36, 595– 610.Google Scholar
Broecker, H. C. & Siems, W. 1984 The role of bubbles for gas transfer from water to air at higher wind speeds: experiments in the wind-wave facility in Hamburg. In Gas Transfer at Water Surfaces (ed. W. Brutsaert & G. H. Jirka), pp. 229– 236. Reidel.
Cheung, T. K. & Street, R. L. 1988 The turbulent layer in the water at an air-water interface. J. Fluid Mech. 194, 133– 151.Google Scholar
Fortescue, G. E. & Pearson, J. R. A. 1967 On gas absorption into a turbulent liquid. Chem. Engng Sci. 22, 1163– 1176.Google Scholar
Hidy, G. M. & Plate, E. J. 1966 Wind action on water standing in a laboratory channel. J. Fluid Mech. 26, 651– 687.Google Scholar
Higbie, R. 1935 The rate of absorption of a pure gas into a still liquid during short periods of exposure. Trans. AIChE 31, 365– 388.Google Scholar
Jähne, B. 1980 Zur parametrisierung des gasaustausches mit hilfe von laborexperimenten. Dissertation, Institut fur Umweltphysik, University of Heidelberg.
Jähne, B., Munnich, K. O. & Siegenthaler, U. 1979 Measurements of gas exchange and momentum transfer in a circular wind-water tunnel. Tellus 31, 321– 329.Google Scholar
Jirka, G. H. & Brutsaert, W. 1984 Measurements of wind effects on water-side controlled gas exchange in riverine systems. In Gas Transfer at Water Surfaces (ed. W. Brutsaert & G. H. Jirka), pp. 437– 446. Reidel.
Kawamura, H. & Toba, Y. 1988 Ordered motion in the turbulent boundary layer over wind waves. J. Fluid Mech. 197, 105– 138.Google Scholar
Komori, S. 1991 Surface-renewal motions and mass transfer across gas-liquid interfaces in open-channel flows. In Phase-Interface Phenomena in Multiphase Flow (ed. G. F. Hewitt, F. Mayinger & J. R. Riznic), pp. 31– 40. Hemisphere.
Komori, S., Murakami, Y. & Ueda, H. 1989 The relationship between surface-renewal and bursting motions in an open-channel flow. J. Fluid Mech. 203, 103– 123.Google Scholar
Komori, S., Nagaosa, R. & Murakami, Y. 1990 Mass transfer into a turbulent liquid across the zero-shear gas-liquid interface. AIChE J. 36, 957– 960.Google Scholar
Komori, S., Nagaosa, R. & Murakami, Y. 1993 Turbulence structure and scalar transfer across a sheared air-water interface in a wind-wave tunnel. In Proc. 4th European Turbulence Conf. (ed. F. T. M. Nieuwstadt). Kluwer (in press.)
Lam, K. & Banerjee, S. 1992 On the condition of streak formation in a bounded turbulent flow. Phys. Fluids A 4, 306– 320.Google Scholar
Liss, P. S. 1973 Processes of gas exchange across an air-water interface. Deep-Sea Res. 20, 221– 238.Google Scholar
Liss, P. S. & Merlivat, L. 1986 Air-Sea gas exchange rates: introduction and synthesis. In The Role of Air-Sea Exchange in Geochemical Cycling (ed. P. Buat-Menard), pp. 113– 127. Reidel.
Luk, S. & Lee, Y. H. 1986 Mass transfer in eddies close to air-water interface. AIChE J. 32, 1546– 1554.Google Scholar
McCready, M. J. & Hanratty, T. J. 1985 Effect of air shear on gas absorption by a liquid film. AIChE J. 31, 2066– 2074.Google Scholar
Mémery, L. & Merlivat, L. 1984 Contribution of bubbles to gas transfer across an air-water interface. In Gas Transfer at Water Surfaces (ed. W. Brutsaert & G. H. Jirka), pp. 247– 253. Reidel.
Merlivat, L. & Mémery, L. 1983 Gas exchange across an air-water interface: experimental results and modeling of bubble contribution to transfer. J. Geophys. Res. 88, 707– 724.Google Scholar
Plant, W. J. & Wright, J. W. 1977 Growth and equilibrium of short gravity waves in a wind-wave tank. J. Fluid Mech. 82, 767– 793.Google Scholar
Rashidi, M. & Banerjee, S. 1990 The effect of boundary conditions and shear rate on streak formation and breakdown in turbulent channel flows. Phys. Fluids A 2, 1827– 1838.Google Scholar
Rashidi, M., Hetsroni, G. & Banerjee, S. 1991 Mechanisms of heat and mass transport at gas-liquid interfaces. Intl J. Heat Mass Transfer 34, 1799– 1810.Google Scholar
Roether, W. & Kromer, B. 1984 Optimum application of the radon deficit method to obtain air-Sea gas exchange rates. In Gas Transfer at Water Surfaces (ed. W. Brutsaert & G. H. Jirka), pp. 447– 457. Reidel.
Smethie, W., Takahashi, T. & Chipman, D. W. 1985 Gas exchange and CO2 flux in the tropical atlantic ocean determined from 222Rn and pCO2 measurements. J. Geophys. Res. 90, 7005– 7022.Google Scholar
Wanninkhof, R. H. & Bliven, L. F. 1991 Relationship between gas exchange, wind speed, and radar backscatter in a large wind-wave tank. J. Geophys. Res. 96, 2785– 2796.Google Scholar
Watson, A. J., Upstill-Goddard, R. C. & Liss, P. S. 1991 Air-Sea gas exchange in rough and stormy seas measured by a dual-tracer technique. Nature 349, 145– 147.Google Scholar
Yoshikawa, I., Kawamura, H., Okuda, K. & Toba, Y. 1988 Turbulent structure in water under laboratory wind waves. J. Oceanogr. Soc. Japan 44, 143– 156.Google Scholar
Zilker, D. P. & Hanratty, T. J. 1979 Influence of the amplitude of a solid wave wall on a turbulent flow. Part 2. Separated flows. J. Fluid Mech. 90, 257– 271.Google Scholar