Experiments on the interface dynamics of stratified air/water flows

For the investigation of co-current two-phase flows, the Horizontal Air/Water Channel (HAWAC) was built at Forschungszentrum Dresden-Rossendorf. A special inlet device provides well-defined as well as variable boundary conditions for generic horizontal two-phase flow experiments. Optical measurements were performed with a high-speed video camera during slug flow. By an interface capture method, the water level can be measured in any observed cross-section. As a result, the water level history can be extracted from the image sequences. Furthermore, the profiles of the time-averaged water level bounded by the standard deviation were presented and show the evolution of the flow structure and of its dynamic component along the channel.