Experiments in a floating water bridge
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In a high-voltage direct-current experiment, a watery connection formed between two beakers filled with deionized water, giving the impression of a ‘floating water bridge’. Having a few millimeters diameter and up to 2.5 cm length, this watery connection reveals a number of interesting phenomena currently discussed in water science. Focusing on optical measurement techniques, the flow through the bridge was visualized and data were recorded such as flow velocity and directions, heat production, density fluctuations, pH values, drag force and mass transfer. To provide a better understanding of the basic phenomena involved the discussion references related literature.
KeywordsTracer Particle Laser Doppler Anemometer Water Bridge Bridge Length Beaker Distance
The authors gratefully acknowledge the support by the Institute of Analytical Chemistry and Food Chemistry, as well as by the Institute of Hydraulic Engineering and Water Resources Management, both at Graz University of Technology, for sharing the NANOpure system and the Photron high-speed camera, respectively, and the support by H. Eisenkölbl (Graz University of Technology). With great pleasure, the authors wish to thank Professors Cees Buisman (Wetsus - Centre of Excellence for Sustainable Water Technology), Emilio Del Giudice (Universitá di Milano), Franz Heitmeir (Graz University of Technology), Jan C.M. Marijnissen (Delft University of Technology) and Gerald H. Pollack (University of Washington) for the ongoing discussion on the water bridge phenomenon (in alphabetic order).
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