Contact

Prof. Dr.-Ing. Dr. h. c. Uwe Hampel

Head
Experimental Thermal Fluid Dynamics
u.hampel@hzdr.de
Phone: +49 351 260 2772

2021 -

Hernandez, J.

Fundamental phenomena in multiphase flows

The development and validation of computational fluid dynamics tools require experimental data with high spatial and temporal resolution. Therefore we conduct experimental studies on fundamental flow phenomena in our thermal hydraulic test facilities TOPFLOW and TOPFLOW+.

Foto: Gas liquid flows in vertical pipes - reference picture ©Copyright: Matthias Beyer

Gas liquid flows in ­vertical pipes

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.
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Foto: Zweiphasige Umströmung von Hindernissen - reference picture ©Copyright: Martin Neumann-Kipping

Two-phase flow around obstacles

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.
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Foto: Stratified flows - reference picture ©Copyright: Matthias Beyer

Stratified two-phase flows

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.
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Foto: critical heat flux - reference picture ©Copyright: Thomas Geißler

Core thermal hydraulics, wall boiling and critical heat flux

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.
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Foto: Deposition and resuspension of nuclear aerosol particles in turbulent flows - reference picture ©Copyright: Dr. Gregory Lecrivain

Deposition and resuspension of nuclear aerosol particles in turbulent flows

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.
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Foto: Experimental investigation of binary granular mixing in a rotating drum using camera and ultrafast X-ray computed tomography - refpic ©Copyright: Theodoros Nestor Papapetrou

Experimental investigation of binary granular mixing in a rotating drum using camera and ultrafast X-ray computed ­tomo­graphy

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.
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Foto: Particle remobilization in urban systems-refpic ©Copyright: Dr. Amir Banari

Particle remobilization in urban systems

Aeroallergens, such as those derived from pollen grains, are known to trigger asthma epidemics. Outbreaks are highly seasonal and their frequency increases in summer. During prolonged urban heat wave, a significant portion of the pollen deposits on urban surfaces.
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Foto: UV ©Copyright: Marco Alejandro Cavagnola

Efficient air cleaning ­techno­logies for se­paration and inactivation of pathogens

Airborne transmission of pathogens became known to a wider public in the context of the COVID-19 pandemic. Recently required applications in hospitals as well as preparedness for future global threats demand the development of efficient air cleaning ­techno­logies for se­parating and inactivating pathogenic aerosol particles.
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