The circular wind wave facilities at the University of Heidelberg

At the University of Heidelberg circular wind/wave flumes are used to study
small-scale air sea interaction processes under a wide range of conditions.
The outer diameter of the large flume is 4m and the channel width is 30 cm.
Wind in the range of 0–12 m/s is generated by a rotating paddle wheel. The
unique circular design yields to homogeneous quasi-infinite fetch conditions.
Since the flume is gas tight and built from transparent PVC, it is
suitable for experiments with various chemical species including acid gases
and surface active materials. The flume accommodates a wide variety of
techniques for noninvasive sensing of waves, water flow, air flow, and gas
exchange. A brief summary of experiments performed within the last twenty
years is given.