X-ray particle tracking velocimetry in liquid foam flow
| Autor: | Tobias Lappan, Sven Eckert, Sascha Heitkam, Holger Schwab, Kerstin Eckert, Uta Kühn, Alexander Franz |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
flow tracer
Materials science business.industry Bubble liquid foam General Chemistry Vorticity Condensed Matter Physics Tracking (particle physics) Rotation 01 natural sciences particle tracking velocimetry 010305 fluids & plasmas Physics::Fluid Dynamics Cross section (physics) Optics Flow velocity Particle tracking velocimetry X-ray radiography 0103 physical sciences 010306 general physics business Beam (structure) |
| Zdroj: | EUFoam 2020, 07.-10.07.2020, Aberystwyth, United Kingdom Soft Matter Soft Matter 16(2020)8, 2093-2103 |
| ISSN: | 2093-2103 |
| Popis: | In this work, we introduce a novel approach to measure the flow velocity of liquid foam by tracking custom-tailored 3D-printed tracers in X-ray radiography. In contrast to optical observations of foam flow in flat cells, the measurement depth equals 100mm in X-ray beam direction. Light-weight tracers of millimetric size and tetrapod-inspired shape are additively manufactured from stainless steel powder by selective laser melting. Matching with the foam structure and bubble size, these tracers follow the foam flow minimally invasively. An X-ray beam passes through the radiotransparent foam channel and is detected by an X-ray image intensifier. The X-ray transmission images show the two-dimensional projections of the radiopaque tracers. Employing particle tracking velocimetry algorithms, the tracer trajectories are measured with both high spatial (0.2 mm) and temporal (25 fps) resolution. Fine-pored and coarse-pored liquid foam flow of different velocities are studied in a partly curved channel with rectangular cross section. The simultaneous time-resolved measurement of the tracers' translational motion and their intrinsic rotation reveal both the local velocity and vorticity of the foam flow. In the semi-circular curved channel section, the rigid-body-like flow pattern is investigated. Moreover, a relaxation of the foam structure in the transition zone between straight and curved section is observed. |
| Databáze: | OpenAIRE |
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