Christian Weiland, M.Sc.


Eissendorfer Str. 38

Building O, Room 3.019

21073 Hamburg

Phone +49 40 42878 - 4644

Mail Christian Weiland


Research

For the optimisation of stirred tank reactors (STR), simulative studies are conducted. The focus is on the determination of the mixing efficiency and the identification of compartments in such vessels. The simulations are carried out utilising the Lattice Boltzmann Method. The further analyses are done with Lagrangian methods, namely the calculation of the arising Finite Time Lyapunov Exponent, the occurring Finite Time Lyapunov Mixing Intensity and the estimation of the network in the observed vessels which directly delivers knowledge about the positions of compartments.

The information retrieved from the Lagrangian analyses is processed further to develop a model describing the observed STR. Additionally, the information concerning the arising deformation of fluid elements, quantified by the Finite Time Lyapunov Exponent, is used for the modelling of multiphase phenomena such as bubble breakup.

Education

Undergraduate and Graduate Teaching Assistant

  • Fundamentals of Fluid Mechanics (Fluid Mechanics I)

  • Fluid Mechanics in Process Engineering (Fluid Mechanics II)

  • Process Design Project (Projektierungskurs), Winter term 2020/2021

Supervised Theses

  • Computational Study of the Influence of Stirrer Configurations on the Lagrangian Mixing in a Stirred Tank Rector (working title), Yvonne Schade, Master’s Thesis, ongoing

  • Numerische Untersuchung des Einflusses ausgewählter Rührervariationen auf das Strömungsverhalten innerhalb eines Rührkesselreaktors, Boran Salli, Bachelor’s Thesis (in supervision coorperation with Ingrid Haase, M.Sc.), ongoing

  • Comparison of the Lattice Boltzmann Method and Finite Volume Method in Continuously Operated Static Mixers - a CFD Benchmark Study, Roman Neubauer, Master's Thesis (in supervision coorperation with Torben Frey, M.Sc.), April 2023

  • Auslegung und Bau eines Wassermühlrades im Labormaßstab zur Ermittlung der abgegeben Leistung im Originalmaßstab unter Berücksichtigung ausgewählter dimensionsloser Kennzahlen (working title), Jarik Koenig, Project Work (in supervision coorperation with Felix Kexel, M.Sc.), ongoing

  • Direkte Numerische Simulation des Grenzflächen-Stofftransports in Blasenströmungen mithilfe einer VOF-Methode, Roberto Flores Cavero, Master's Thesis (in supervision coorperation with PD Dr.-Ing habil. Yan Jin), July 2022

  • Untersuchung von Transportbarrieren innerhalb eines kontinuierlichen Rührkesselreaktors unter Verwendung dreidimensionaler Lagrangescher Kohärenter Strukturen, Eike Steuwe, Master's Thesis (in supervision coorperation with Prof. Dr. Alexandra von Kameke), May 2022

  • Ermittlung der Leistungsabgabe eines Wassermühlenrades unter Verwendung numerischer Strömungssimulation, Alexander Hanke, Project work, April 2022

  • Charakterisierung der Totzeitverteilung in Rührkesselreaktoren mittels numerischer Strömungssimulation mit der Lattice-Boltzmann Methode, Mustafa Salli, Bachelor's Thesis, March 2022

  • Mehrzieloptimierung einer durchströmten offenen Struktur unter Anwendung des diskreten Adjungiertenverfahrens mittels numerischer Strömungssimulation, Mona Abbas Sayed Omar, Master's Thesis (in supervision coorperation with Claas Spille, M.Sc.), January 2022

  • Nichtinvasive Bestimmung des portosystemischen Druckgradienten nach TIPS-Implantation: Vergleich von stationären und transienten numerischen Strömungssimulationen, Muhammad Ismahil, Master's Thesis (in supervision coorperation with Dr.-Ing. Marko Hoffmann and close coorperation with Dr. med. Christoph Riedel (UKE)), December 2021

  • Analyse von Einflussparametern auf den portosystemischen Druckgradienten nach TIPS-Implantation mittels numerischer Strömungssimulation, Eleonora Abu Rashed, Master's Thesis (in supervision coorperation with Dr.-Ing. Marko Hoffmann and close coorperation with Dr. med. Christoph Riedel (UKE)), May 2021

  • Geometrieoptimierung unter Nutzung numerischer Simulation mittels Verwendung des ANSYS Adjoint Solvers, Mona Abbas Sayed Omar, Project Work (in supervision coorperation with Claas Spille, M.Sc.), March 2021

  • Numerische Simulation der Fluiddynamik unter Berücksichtigung der Mischcharakteristik eines nicht-newtonschen Fluides innerhalb einer industriellen Mischapparatur, Simon Abraha, Master's Thesis, July 2020

  • Bewertung einer neuen Methode zur nichtinvasiven Messung von dynamischen Temperaturverläufen mittels numerischer Strömungssimulation, Hanno Hagenström, Master's Thesis, Dezember 2019

  • Prediction of the Mass Transfer Coefficient Based on the Eddy Cell Model for an Aerated Stirred Tank Reactor under Multiple Operating Conditions, Hendrick Jansen, Master's Thesis, November 2019

Oral and Poster Presentations

Oral Presentations

  • Weiland, C.; Steuwe, E.; von Kameke, A.; Hoffmann, M.; Schlüter, M.:“ Identification of Compartments in Stirred Tank Reactors by Analysing Lagrangian Coherent Structures From Velocity Fields Derived by the Lattice-Boltzmann-Method”, 11th International Conference of Multiphase Flow 2023, Kobe, oral presentation

  • Weiland, C.; Hofmann, S.; Fitschen, J.; von Kameke, A.; Hoffmann, M.; Schlüter, M.: "Numerische Simulation Lagrangescher Partikeltrajektorien und Charakterisierung des Partikelfolgevermögens in einem 3 L Rührkesselreaktor", ProcessNet Jahrestreffen CFD, Mischen und Agglomeration 2022, Leipzig, oral presentation

  • Hofmann, S.; Weiland, C.; Fitschen, J.; von Kameke, A.; Hoffmann, M.; Schlüter, M.: "Vergleich von experimentellen und numerischen Untersuchungen zur Abschätzung des Folgevermögens verschiedener Lagrange’scher Partikel in der Bioreaktorströmung", ProcessNet Jahrestreffen CFD, Mischen und Agglomeration 2022, Leipzig, oral presentation

Poster Presentations

  • Hofmann, S.; Weiland, C.; GopalSingh, P.; Kamp, M.; Fitschen, J.; v. Kameke, A.; Hoffmann, M.; Schlüter, M.: "Experimental and numerical determination of lifelines in a 3 L, 200 L and 15000 L stirred tank reactor to estimate the flow-following capability of Lagrangian Sensor Particles", MIXING XXVII, North American Mixing Forum (NAMF), Online Conference 2022, virtual poster presentation

  • Weiland, C.; Fitschen, J.; Hoffmann, M.; Schlüter, M.:"Numerical Simulation and Validation of the Bubble Size Distribution in an Aerated Stirred Tank Reactor", ProcessNet Jahrestreffen Mehrphasenströmungen & CFD 2021, virtual poster presentation

  • Weiland, C.; Hoffmann, M.; Schlüter, M.: "Numerical Simulation of the Mixing Time and Pathlines of Lagrangian Tracer Particles in a Stirred Tank Reactor", Hamburg-Bochumer Mehrphasensymposium, 2020, virtual poster presentation

Publications

[179106]
Title: Computational study of three-dimensional Lagrangian transport and mixing in a stirred tank reactor.
Written by: Weiland, C.; Steuwe, E.; Fitschen, J.; Hoffmann, M.; Schlüter, M.; Padberg-Gehle, K.; von Kameke, A.
in: <em>Chemical Engineering Journal Advances</em>. (2023).
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DOI: https://doi.org/10.1016/j.ceja.2023.100448
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Abstract: The detection of compartments and dead zones as well as the estimation of the mixing efficiency in stirred tanks are of vital interest for a variety of biochemical and chemical processes. Here, numerically derived time-dependent 3D fluid velocity fields of a stirred tank reactor are computed using the Lattice Boltzmann Method. Mixing in the stirred tank reactor is analysed by means of Lagrangian Coherent Structures which allow to unravel the mixing states of complex flows. This Lagrangian analysis is achieved by computing Finite Time Lyapunov Exponents and applying recent trajectory-based network methods on the three-dimensional flow. The results reveal a zone of low interaction in the upper region of the stirred tank reactor and five additional transient compartments. The trajectory-based network analysis detects low cross-mixing of fluid parcels between different compartments but a very high mixing of fluid parcels inside of each compartment. This high interaction is also found in an analysis of the Finite Time Lyapunov Mixing Intensity. Time-averaging of the fluid velocity field prior to the Lagrangian analysis is considered to extract the most influential Lagrangian Coherent Structures.