Mohri Group - Tomography

We are a young and energetic group that focuses on developing and applying tomographic techniques to produce instantaneous three-dimensional (3D) information from experiments in energy- and process-technology research. Such information is paramount to deepen our understanding of various phenomena in real flows, which are almost always unsteady or turbulent. In turn, this allows us to improve different technologies such as combustion devices, to be made more efficient or environmentally friendly.  

We combine different types of measurements with computed tomography (CT), including background-oriented schlieren (BOS) that is relevant in reactive and non-reactive flows, and radiative emission in combusting gases. Our generic multi-camera setup allows us to produce unprecedented reconstructions based on multi-simultaneous measurements. This enables us to investigate different effects within the same volume, and such information is rarely available experimentally.

We develop techniques for both laboratory settings, which are ideal for fundamental studies, and for the more challenging industrial environments where accessibility is almost always limited. We constantly develop and test our algorithms through diverse applications and phantom studies. A phantom is an exactly known field that can be compared to its reconstruction, allowing for a quantitative assessment of the reconstruction. We use realistic phantoms, for example from flow simulations, that represent the complexity of the fields that we aim to reconstruct. If you would like to find out more about our tomography techniques, are interested in applying our techniques to an experiment, or any other enquiries about our group please do not hesitate to contact us by sending an email to khadijeh.mohri [at] uni-due.de.    

Group Leader

Mohri 202007-ude

Prof. Dr. Khadijeh Mohri
Phone: +49-(0)203-379 8124
khadijeh.mohri[at]uni-due.de
Room: NETZ 1.10

Research Associates

Andreas Unterberger Sw

Andreas Unterberger
Phone: +49-(0)203-379 8120
andreas.unterberger[at]uni-due.de
Room: NETZ 1.18

 

Students

  • Ms. Cheau Tyan Foo, Bachelor thesis (2019): Simultaneous multi-colour flame tomography of turbulent stratified flames.
  • Mr. Zachary Emuang, Bachelor thesis (2019): Generation of noise patterns for flame tomography based on background-oriented schlieren analysis
  • Ms. Yinyi Kwong, Bachelor thesis (2019)
  • Mr. Stanislaw Yaroshevskyy, Master thesis (2018): Design of a precision 3D camera mount.
  • Mr. Alexander Kassen, Bachelor thesis (2018): Adapting the tomographic setup to generate frozen flame movies for analysing the dynamics of a turbulent flame.
  • Mr. Andreas Unterberger, Master thesis (2018): 3D Evolutionary reconstruction of scalar fields: Phantom study and application to a stratified flame.
  • Mr. Manuj K. Yadav, Masters thesis (2017): Influence of low pressure exhaust gas recirculation (LP-EGR) on a turbocharger compressor - a numerical analysis
  • Mr. Julien Verbeke, Masters thesis (2017): Computed tomography of a swirl flame’s chemiluminescence field and LES-phantom study on effect of out-of-plane views

Visiting Scholars

  • Dr. Samuel Grauer, Georgia Institute of Technology, USA
  • Ms. Jin Ying, Nanjing University of Science and Technology (NJUST), China
  • Mr. Emeric Boigné, Stanford University, USA

Collaborations


Universities and research institutes

  • Gas und Wärme Institut GWI (Germany)
  • Georogia Institute of Technology (USA)
  • Hochschule Darmstadt (Germany)
  • Nanjing University of Science and Technology (China)
  • Newcastle University (UK)
  • Stanford University (USA)
  • Technische Universität Darmstadt (Germany)
  • University of Waterloo (USA)


Industry

  • Airbus Defence and Space GmbH (Germany)
  • Continental (Germany)

Gallery

 

Tomo Flame


 

Multi-colour vaporised salt seeding into the dual annular slots of the Cambridge-Sandia stratified burner7.
​​

Mohri Flame Reconstruction Arb
 

Computed Tomography of Chemiluminescence (CTC) reconstruction of the instantaneous 3D chemiluminescence field of a highly turbulent swirl-stabilised flame (equivalence ratio ɸ = 1.0)1.

Ert 2

Evolutionary Reconstruction Technique (ERT), the 3D chemiluminescence field of the Cambridge-Sandia flame SwB1.

 

 

Setup


 

Generic multi-camera setup for tomography.

 

 

 

Bos Bunsen



 

Background-Oriented Schlieren Tomography (BOST)


Cross-section slices of the swirl flame chemiluminescence reconstruction (3D field above), at different heights above the burner z normalised by the burner bluff body diameter DT1.

Events

Girl's day at UDE 2019

Girlsday Photo

Reviewed Journal Publications

  1. K. Mohri, S. Görs, J. Schoeler, A. Rittler, T. Dreier, C. Schulz and A. Kempf. Instantaneous 3D-imaging of highly turbulent flames using Computed Tomography of Chemiluminescence, Applied Optics 56, 7385-7395 (2017).
  2. S. J. Grauer, A. Unterberger, A. Rittler, K. J. Daun, A. M. Kempf and K. Mohri. Instantaneous 3D flame imaging by backgrounded-orientated schlieren tomography, Combustion and Flame 196, 284 (2018).
  3. S. J. Grauer, A. Unterberger, K. J. Daun, K. Mohri. Demonstration of instantaneous 3D flame reconstruction by background-orientated schlieren tomography. Proceedings of the Combustion Institute - Canadian Section, spring technical meeting, Toronto, Canada (2018).
  4. A. Unterberger, M. Röder, A. Giese, A. Al-Halbouni, A. Kempf and K. Mohri. 3D instantaneous reconstruction of turbulent industrial flames using Computed Tomography of Chemiluminescence (CTC), Journal of Combustion special issue on Coal and Biomass Combustion,doi:https://doi.org/10.1155/2018/5373829 (2018). 
  5. A. Unterberger, A. Kempf and K. Mohri. 3D evolutionary reconstruction of scalar fields in the gas-phase. Energies 12:11, doi: https://doi.org/10.3390/en12112075 (2019).
  6. A. Unterberger, J. Menser, A. Kempf, K. Mohri. Evolutionary camera pose estimation of a multi-camera setup for computed tomography, proceedings of the IEEE International Conference on Image Processing, Taipei, Taiwan (2019).
     
  7. C. T. Foo, A. Unterberger, J. Menser, K. Mohri. Simultaneous multi-colour flame tomography. In preparation.

Conference Contributions

  1. J. Menser, A. Unterberger, K. Mohri. Convolutional neural networks for camera calibration requirements in flame tomography. Oral presentation at the 29th Deutscher Flammentag (German flame day), Bochum (Sep. 2019).
  2. A. Unterberger, A. Kempf, K. Mohri. Phantom studies on a new evolutionary reconstruction technique applied to 3D scalar fields in the gas-phase. Poster at the 9th European Combustion meeting, Lisbon, Portugal (Apr. 2019).
  3. A. Unterbeger, J. Menser, A. Kempf, K. Mohri. 3D evolutionary reconstruction of scalar fields: phantom study and application to a stratified flame. Poster at the 37th International Symposium on Combustion, Dublin, Ireland  (Jul.-Aug. 2018).
  4. K. Mohri, J. Menser, A. Kempf, J. Trabold, S. Walther, D. Geyer. Instantaneous 3D imaging of the Temperature Controlled Piloted Jet Burner (TCPJB) flames using computed tomography of chemiluminescence (CTC). Poster at the 37th International Symposium on Combustion, Dublin, Ireland  (Jul.-Aug. 2018).
  5. S. J. Grauer, A. Unterberger, T. A. Sipkens, A. M. Kempf, K. J. Daun. K. Mohri. Background-oriented schlieren tomography for instantaneous 3D combustion imaging. Poster at the 37th International Symposium on Combustion, Dublin, Ireland  (Jul.-Aug. 2018).
  6. J. Menser, A. Unterberger, L. Cifuentec, A. Kempf, K. Mohri. Quantifying flame tomography reconstructions with the aid of DNS phantom data. Poster at the 37th International Symposium on Combustion, Dublin, Ireland  (Jul.-Aug. 2018).
  7. J. Menser, A. Unterberger, A. Kemp and K. Mohri. Instantaneous 3D imaging of turbulent stratified methane/air flames using computed tomography of chemiluminescence. Proceedings of the 5th International Conference on Experimental Fluid Mechanics (ICEFM), Munich (July 2-4, 2018).
  8. J. Menser, A. Unterberger, S. Grauer, A. Kempf and K. Mohri. Volumetric imaging of turbulent stratified premixed flames using tomography, background-orientated schlieren and high-speed imaging. Poster, Centre for Nano Integration Duisburg-Essen (CENIDE) conference, Bergische Gladbach (Feb. 2018).
  9. K. Mohri, M. Röder, A. Giese, A. Al-Halbouni and A. Kempf. 3D instantaneous reconstruction of a turbulent industrial burner flame using Computed Tomography of Chemiluminescence (CTC). Oral presentation, 3rd General Meeting and Workshop on SECs in Industry COST Action 1404 of the European Cooperation in Science and Technology, Prague (Oct. 2017).
  10. K. Mohri, M. Röder, A. Giese, A. Al-Halbouni, A. Kempf. Computed Tomography of Chemiluminescence (CTC): reconstructing turbulent laboratory and industrial flames. Poster, 28th Deutscher Flammentag, Darmstadt (Sep. 2017).
  11. J. Verbeke, A. Rittler, S. Görs, C. Schulz, A. Kempf and K. Mohri. Computed Tomography of Chemiluminescence (CTC): Effect of out-of-plane views on the quality of three-dimensional reconstruction of a turbulent swirl flame. Poster and paper, 8th European Combustion Meeting, Croatia (April 2017).
  12. K. Mohri, S. Görs, J. Schöler, T. Dreier, C. Schulz and A. Kempf. Tomographic reconstruction of the highly turbulent TECFLAM and unsteady Bunsen flames’ 3D instantaneous chemiluminescence field. Poster, 36th International Symposium on Combustion (2016).
  13. K. Mohri, A. Kempf. Computed tomography of chemiluminescence in asymmetric unsteady premixed flames. Poster and paper, 27th Deutscher Flammentag, VDI-Berichte Nr. 2267 (2015) 729-734.
  14. K. Mohri and A. Kempf. Computed tomography of chemiluminescence for 3D reconstructions of quasi-steady premixed flames. Talk and poster, Combustion Institute (British section) meeting, Imperial College London (2014).