Towards Fluid Dynamics of Foam and Froth

Emmy-Noether ©Copyright: DFG

Emmy Noether research group of Dr.-Ing. Heitkam, Sascha

funded by DFG, start: 05/2020


Motivation: Foam flow is not yet sufficiently understood because it is defined by the complex interaction of mechanisms at different length scales. At the same time, measurement techniques are scarcely available because established flow measurement techniques are not applicable to foam and froth.

Multi scale mechanism of foam flow ©Copyright: Dr. Heitkam, Sascha

In Stage I, this Emmy-Noether research group aims to develop and adapt innovative measurement techniques to foam flow.

In Stage II, flow experiments in generic as well as industrially motivated configurations will be carried out.

Stage I

Electrical Impedance Tomography is adapted to measure the liquid distribution in foam with high spatial and temporal resolution.

Impedance tomography ©Copyright: Dr. Heitkam, Sascha

X-ray Particle-Tracking-Velocimetry with custom-shaped 3D-printed tracer particles allows to measure the velocity distribution and vorticity inside a foam sample

X-ray particle tracking ©Copyright: Dr. Heitkam, Sascha

The ROFEX facility of HZDR (Ultrafast electron beam X-ray computed tomography (ROFEX)) will be employed to measure velocity and particle distribution inside a foam flow channel.

ROFEX of froth ©Copyright: Dr. Heitkam, Sascha

Stage II

The wash-water distribution in froth flotation will be researched and optimised with Conductivimetry. The efficiency of particle removal will be tested.

Generic foam flows will be used to compare measurement techniques and create Benchmarks for further development

Turbulence in foam flow has never been documented. Large-scale flow experiments will yield first insights into foam turbulence.


Heitkam, S., & Eckert, K. (2021). Convective instability in sheared foam. Journal of Fluid Mechanics, 911.

Lappan, T., Franz, A., Schwab, H., Kühn, U., Eckert, S., Eckert, K., & Heitkam, S. (2020). X-ray particle tracking velocimetry in liquid foam flow. Soft matter, 16(8), 2093-2103.

Heitkam, S., Lappan, T., Eckert, S., Trtik, P., & Eckert, K. (2019). Tracking of particles in froth using neutron imaging. Chemie Ingenieur Technik, 91(7), 1001-1007.