Hydrogen bubble method
The hydrogen bubble method is a method of visualizing flows. This can be used to create timelines in flowing water.
The method is based on the electrolysis of water. A fine wire is positioned in the water, which is usually made of platinum and has a thickness of 10 to 40 µm. A counter electrode is placed in a non-disruptive location in the flow field.
In the experiment, the wire as the cathode and the counter electrode as the anode are briefly exposed to electrical voltage . Tiny hydrogen bubbles form on the wire , which swim with the current and create time lines. These timelines can be photographed and evaluated photogrammetrically . The vesicles dissolve again with a half-life of about three seconds.
The method is suitable for flow velocities of around 0.5 to 30 cm / s. The buoyancy of the bubbles can be neglected less and less at lower flow speeds.
The hydrogen bubble method was first described by Jonathan Zenneck in 1914 .
literature
- Helmut Eckelmann: Introduction to flow measurement technology. Teubner, Stuttgart 1997, ISBN 3519023792 , p. 265 ff.
Individual evidence
- ↑ H. Eckelmann: Introduction to flow measurement technology. With reference to: J. Zenneck: Demonstration and photography of currents inside a liquid. Relation to German Phys. Braunschweig, Volume 16, No. 14 (1914) 695-698.