Simulation programs for one- and three-dimensional flows provide good results for single-phase flows. But in two-phase flows and in complex geometries the quality of flow prediction is often insufficient. This can be improved by measurements in high temporal and spatial resolution.

This project deals with high-resolution visualization of co-current two-phase flows in upward ­vertical pipe flows with an orifice. For the experiments ultrafast X-ray ­tomo­graphy is applied as imaging technique.

The investigation of tratified two-phase flows is ­very important for the evaluation of the mass- and energy transfer in technical devices and units. For instance the size of the interfacial area influences the reaction rate in chemical reactors considerably.

Together with the other project partners the transient process from nucleate boiling to film boiling is studied both by means of experimental and numerical tools. Numerical method development includes the modelling of the development of gas fraction, bubble size and distribution and heat transfer in the Euler-Euler two-phase framework near or at CHF.

The transport, deposition and resuspension behaviour of carbonaceous dust in the primary circuit of a High Temperature Reactors (HTR) is a fundamental safety issue for the development and safety assessment of such a reactor.

The mixing of two granular species is central to a variety of industrial processes. Notable examples include the mixing of dry granular products in the pharmaceutical, chemical and food processing industry using ap­paratuses such as mixing drums.