Comparative heat and gas exchange measurements in the Heidelberg Aeolotron, a large annular wind-wave tank
A comparative study of simultaneous heat and gas exchange measurements was performed in the large annular Heidelberg Air–Sea Interaction Facility, the Aeolotron, under homogeneous water surface conditions. The use of two gas tracers, N<sub>2</sub>O and C<sub>2</sub>HF<sub&...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-01-01
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| Series: | Ocean Science |
| Online Access: | http://www.ocean-sci.net/11/111/2015/os-11-111-2015.pdf |
| Summary: | A comparative study of simultaneous heat and gas exchange measurements was
performed in the large annular Heidelberg Air–Sea Interaction Facility, the
Aeolotron, under homogeneous water surface conditions. The use of two gas
tracers, N<sub>2</sub>O and C<sub>2</sub>HF<sub>5</sub>, resulted not only in gas transfer
velocities, but also in the measurement of the Schmidt number exponent n
with a precision of ±0.025. The original controlled flux, or active
thermographic, technique proposed by Jähne et al. (1989) was applied by
heating a large patch at the water surface to measure heat transfer
velocities. Heating a large patch, the active thermography technique is
laterally homogeneous, and problems of lateral transport effects are avoided.
Using the measured Schmidt number exponents, the ratio of the scaled heat
transfer velocities to the measured gas transfer velocities is 1.046 ±
0.040, a good agreement within the limits of experimental uncertainties.
This indicates the possibility to scale heat transfer velocities measured by
active thermography to gas transfer velocities, provided that the Schmidt number
exponent is known and that the heated patch is large enough to reach the
thermal equilibrium. |
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| ISSN: | 1812-0784 1812-0792 |