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Gas Transfer at Air-Water Interface



Experimental tank with the PIV laser (white) and camera (blue).  


Gas transfer across the air-water interface plays an important role in nature as well as in man made facilities.  The absorption of  CO2 into the ocean, the absorption of oxygen into natural streams and the stripping of H2S in drinking water treatment are examples of this process. It is already well known that turbulence can enhance the gas transfer. The interaction between bottom shear induced turbulence and oxygen absorption from air into water has been investigated (completed project supported by DFG). The ongoing study focuses on the gas transfer process in water environment dominated by buoyant-convection turbulence.


Experimental works are conducted in a plexiglass tank equiped with glass windows to enhance optical access.  The Particle Image Velocimetry (PIV) and the Laser Induced Fluorescence (LIF) techniques are applied to acquire the instantaneous velocity and concentration fields respectively.  The LIF technique is used with an oxygen quenching method that enables quantification of the dissolved oxygen concentration distribution.  Besides having the advantages of being non-intrusive and instantaneous, the PIV and LIF techniques may be coupled together providing a simultaneous measurements of velocity and concentration which then allows the computation of turbulent mass flux.




Niepelt, A., Herlina, H. & Jirka, G.H. (2009).  "Gas transfer at the air-water interface induced by buoyant convection," Interim Report, Institutsbericht Nr. 843, Inst. f. Hydromech., Univ. Karlsruhe.

Niepelt, A., Herlina, H. & Jirka, G.H. (2009). "Visualization of gas transfer process induced by natural buoyant convection", Fifth Int. Symposium on Gas Transfer at Water Surfaces, 2010, Kyoto, Japan, will be submitted.

Herlina and G.H. Jirka (2008). "Experiments on gas transfer at the air-water interface induced by oscillating grid turbulence."  J. Fluid Mech., Vol.594, pp.183-208.

Jirka, G.H., Herlina (2008). "Ecological Processes: Reaeration", In Sven Erik Jorgensen & Brian D. Fath, Encyclopedia of Ecology, 1st Edition, Elsevier B.V., Oxford, pp. 2975-2981.

Herlina, Jirka, G.H. & Murniati, E. (2007). "Oxygen transfer dominated by buoyant convective instability", Proc. Fifth Int. Symposium on Environmental Hydraulics, D. Boyer (Ed.), Tempe, Arizona, CD-ROM

Herlina and G.H. Jirka (2007). “Turbulent gas flux measurements near the air-water interface in a grid-stirred tank.” In C.S. Garbe, R.A. Handler, and B. Jähne, editors, Transport at the Air Sea Interface - Measurements, Models and Parameterizations. Springer Verlag.

Murniati, E. (2006). "Oxygen transfer dominated by buoyant-convective instability in windless lakes", Master Thesis, Master Program Resources Engineering / University of Karlsruhe.

Herlina (2005). "Gas transfer at the air-water interface in a turbulent flow environment." Doctoral Thesis, Institute for Hydromechanics, University of Karlsruhe, University Press ISBN 3-937300-74-0.

Herlina and G.H. Jirka (2004). "Application of LIF to investigate gas transfer near the air-water interface in a grid-stirred tank." Exp. Fluids, Vol. 37, pp. 341-349.

Herlina, Kühn, G. & Lang, C. (2001).  "Turbulenzverteilung in einem Rüttelgittertank  - Einsatz der PIV-Messtechnik", Institutsbericht Nr. 788, Inst. f. Hydromech., Univ. Karlsruhe.