Work package 5.3 - X-ray tomography imaging
Principal Investigator: Dr. M. Bieberle (Technische Universität Dresden)
PhD student: Dipl.-Math. Michael Wagner
Main Scientific Goals:
Ultrafast X-ray tomography shall be qualified as quantitative measurement technique for the analysis of multiphase flows in structured elements up to 100 mm diameter. The measurement system itself with its temporal resolution of up to 5,000 fps and its spatial resolution of about 1 mm has already been successfully applied to various multi-phase flow experiments, such as two-phase pipe flows, slurry and conventional bubble columns and fluidized beds. The main objectives of this work package are therefore focused on adapted data analysis methods for structured elements and their evaluation. The most important outcome parameters of the analysis are gas phase distribution, phase boundaries and gas residence time.
- Implementing the ultra-fast X-ray tomography system at the test facility
- Transforming reconstructed grey-value images into phase concentration images by adapted scaling
- Correction of non-linear image artefacts caused by scattering and beam hardening by an algorithm based on ray-tracking, which simulates first-order scattering
- Mapping high-resolution CT images of foam structures onto ultra-fast CT images by sophisticated correlation methods in order to identify maldistribution and dead zones related to structural parameters
- Extraction of physical phase boundaries from binarized 3D-image data for the further analysis of flow dynamics and calculation of important parameters such as mass transfer coefficient
|Combination of ultra-fast CT data and high-resolution CT data by an algorithm, which correlates the positions of local gray-value maxima|
Correction of scattering artefacts: Estimated scattering artefact of an aluminum plate (left), which was scanned with a high resolution gamma-ray tomography system and the corresponding horizontal gray-value profiles (right)
Measurement of trickling water in a foam structure: The experimental facility has been installed in the ultra-fast X-ray tomography system (top left). The foam (top middle) was scanned with ultra-fast X-ray tomography in different heights (cross-sectional images at the bottom). A stationary flow field with high hold-up at the bottom developed during the experiment. The three-dimensional image (top right) consists of numerous cross-sectional images from different heights.
WP 3.1, 4.4, TUHH (Hamburg), FAU (Erlangen), RUB (Bochum)
- M. Wagner, A. Bieberle, U. Hampel, 2013. Study on a simulation-based scatter correction for high-resolution gamma-ray tomography, 7th World Congress on Industrial Process Tomography, WCIPT7, 02.-05.09.2013, Krakow, Poland, 2013.
- M. Bieberle, T. Stürzel, U. Hampel, E. Laurien, Ultrafast 3D X-ray tomography of a wire-mesh sensor in operation in a two-phase flow, 7th World Congress on Industrial Process Tomography, WCIPT7, 02.-05.09.2013, Krakow, Poland, 2013.