Towards Fluid Dynamics of Foam and Froth
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.
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Objectives
- Develop and adapt measurement techniques for foam
- Research foam flows in generic configurations
- Identify and quantify unique flow features of foam
Measurement Techniques
- X-ray Particle-Tracking-Velocimetry with custom-shaped 3D-printed tracer particles allows to measure the velocity distribution and vorticity inside a foam sample
- WIre-Mesh sensors with adapted calibration for measuring liquid fraction distribution with spatial and high temporal resolution
- Neutron radiography reveals liquid fraction as well as particle concentrations in foam and froth
- Bubble size measurement by automated image segmentation and optical stress measurement
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Generic foam flows
- Flow around a cylinder in a vertical foam column
- Flow through nozzles and diffusors
- Flow in a semi-annulus
Foam features
- Layered structure of bubbles near walls
- Anisotropic drainage in sheared foam
- Bubble size sorting in foam columns
Publications
Knüpfer, L., Götzelt, R., Eckert, K., & Heitkam, S. (2024). Radial bubble size distributions in a rising foam column. Chemical Engineering Research and Design, 208, 336-347.
Skrypnik, A., Heitkam, S., Gerstenberg, C., Morelle, E., McHardy, C., & Rauh, C. (2024). Optical measurement of the shear stress and velocity distribution in an idealized deglutition process. Journal of Food Engineering, 365, 111849.
Knüpfer, L., Eckert, K., & Heitkam, S. (2024). A comparative study on the measurement of surface bubble size distributions in dry aqueous foams using optical methods. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 680, 132507.
Skrypnik, A., Cole, K., Lappan, T., Brito-Parada, P. R., Neethling, S. J., Trtik, P., ... & Heitkam, S. (2024). Neutron radiography of an anisotropic drainage flow. Physical Review E, 109(1), 014609.
Lappan, T., Herting, D., Ziauddin, M., Stenzel, J., Shevchenko, N., Eckert, S., ... & Heitkam, S. (2023). X-ray Particle Tracking Velocimetry in an Overflowing Foam. Applied Sciences, 13(3), 1765.
Skrypnik, A., Knüpfer, L., Trtik, P., Tholan, V., Parkes, S., & Heitkam, S. (2023). Neutron radiography of liquid foam structure near a vertical wall. Soft Matter, 19(44), 8552-8560.
Ziauddin, M., Schleicher, E., Trtik, P., Knüpfer, L., Skrypnik, A., Lappan, T., ... & Heitkam, S. (2022). Comparing wire-mesh sensor with neutron radiography for measurement of liquid fraction in foam. Journal of Physics: Condensed Matter, 35(1), 015101.
Knüpfer, L., & Heitkam, S. (2022). A machine learning approach to determine bubble sizes in foam at a transparent wall. Measurement Science and Technology, 33(6), 067001.
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.