Jürgen Fitschen, M.Sc.

Eißendorfer Str. 38, Building O, Room 112

Telephone +49 40 42878-2031

E-Mail: Jürgen Fitschen, M.Sc.



In any case of mammalian cell expression systems it is of vital importance to ensure ideal growth conditions. In general, to achieve high product qualities and efficiencies, a constant feed and oxygen supply and a homogeneous mixing behavior have to be guaranteed during the entire process time as well as overall upstream processes. For a reliable design and scale up a profound understanding of hydrodynamics and mass transfer is required. 

At the Institute of Multiphase Flows (IMS) at the Hamburg University of Technology various studies have been performed to study the influence of different operation conditions as well as stirrer geometries on mixing efficiency, mass transfer performance and power input on laboratory (0.002 and 0.03 m 3 ) and industrial scale (15 m 3 ). This work gives deep insights into the hydrodynamic behavior and a characterization of an industrial scale aerated stirred tank reactor.



Assistance of graduate course: Fluid Mechanics in Process Engineering


Supervised Theses:

Current Theses:

„Visualisation of streamlines in aerated stirred tank reactors - a feasibility study for the application of 2D-PTV in industrial scale"(working title), Marcus Schewe, bachelor thesis

„Experimental Determination of Shear Rate in a 3L Aerated Stirred Tank Reactor by Means of Shear Sensitive Particles“(working title), Zeynep Persin, master thesis


Completed Theses:

„Experimental Determination of Power Input and Mixing Characteristics of Various Stirrer Combinations in a Lab-Scale Aerated Stirred Tank Reactor “, Vincent Bernemann, bachelor thesis, 2019

„Experimental Determination of Bubble Size Distributions and Oxygen Mass Transfer Performances to Evaluate Scale-Up Rules for Aerated Stirred Tank Reactor in Lab- and Pilot-Scale “Ezgi Arslanturkoglu, master thesis, 2019

„Design and Construction of a 30 L Aerated Stirred Tank Reactor on a Pilot Scale and Experimental Determination of Power Input and Mixing Performance for Different Stirrer Configurations“, Benjamin Cardenas, master thesis, 2019

„Numerische Simulation der Mischcharakteristik eines Rührkesselreaktors im industriellen Maßstab mittels verschiedener Turbulenzmodelle“, Christian Weiland, master thesis, 2019

„Experimental Determination of Local Bubble Size Distributions in Aerated Stirred Tank Reactor on a Pilot Scale“, Lisa Christin Watter, project thesis, 2018

„Experimenteller Vergleich von dynamischen und stationären CO2 Stoffübergangsmessungen in begasten Rührkesselreaktoren im Labor- und Industriemaßstab“, Kai Heitmann, master thesis, 2018

„Experimentelle Untersuchung zum Gasgehalt begaster Rührkesselreaktoren im Industriemaßstab“, Xiye Zhou, bachelor thesis, 2018

„Experimental Determination of Relative Humidity in the Exhaust Gas Stream of an Industrial Scale Aerated Stirred Tank Reactor“, Ezgi Arslanturkoglu, project thesis, 2018



Fitschen, J.; Rosseburg, A.; Wucherpfennig, T.; Wutz, J.; Schlüter, M.: Visualization of Mixing Performance and Measurements of Power Input in Aerated Stirrd Tank Reactors - Comparison of Laberatory and Industrial Scale, 10th International Conference on Multiphase Flow (ICMF 2019), Rio de Janeiro, Brazil, 2019, oral presentation

Fitschen, J.; Rosseburg, A.; Wucherpfennig, T.; Wutz, J.; Schlüter, M.: Bioprocesses Made Transparent - Stirring on Industrial Scale - Deep Insights and Characterization, Jahrestreffen der ProzessNet-Fachgruppen Mischvörgänge, Trocknungstechnik und Wärme- und Stoffübertragung, Essen, 2019, oral presentation

Rosseburg, A.; Fitschen, J.; Wutz, J.; Wucherpfennig, T.; Schlüter, M.: Hydrodynamic inhomogeneities in large scale stirred tanks – Influence on mixing time,Chemical Engineering Science, 2018, 188, 208-220, DOI: 10.1016/j.ces.2018.05.008

Rosseburg, A., Fitschen, J., Wutz, J., Wucherpfennig, T., Schlüter, M., „Influence of local flow structure on the mixing behaviour within an aerated 12 000L stirred tank reactor”, Jahrestreffen der ProcessNet Fachgruppe Mischvorgänge, Munich 2018, Germany

Fitschen, J.; Rosseburg, A.; Wucherpfennig, T.;Wutz, J.; Schlüter, M.: Verfahren zur optischen Bestimmung von lokalen Konzentrationsgradienten in einem gläsernen 15 kL begasten Rührkesselreaktor., Gemeinsamen Jahrestreffen MPH, WSUE & CFD, Bremen, Germany, 2018, poster presentation.

Fitschen, J.; Rosseburg, A.; Wucherpfennig, T.; Wutz, J.; Schlüter, M.: Visualization of mixing in an acrylic 12000L aerated stirred tank reactor, 10th World Congress of Chemical Engineering, Barcelona, Spain, 2017, poster presentation.