Address:

Ulm University
Department of Numerical Mathematics
Helmholtzstraße 20 (Room 1.04)
89081 Ulm, Germany
Germany

Contact:

Phone: +49 (0)731 / 50-23937
Fax: +49 (0)731 / 50-23548
Jonas Unger

Field of Research:

A large number of technical applications include chemically reactive flows comprising an interplay between convective and diffusive species transport and chemical reaction processes. In many realistic kinetic models the occurence of a large number of chemical species and reactions as well as a high degree of stiffness due to multiple time scales give rise to significant challenges for numerical simulations and call for multi-scale approaches and model reduction techniques. 
The goal of this project is the development of a practical numerical reduction technique that can be applied to high-dimensional realistic chemical reaction mechanisms and automatically computes slow invariant manifolds (SIM) as low-dimensional approximations of long-term system dynamics in chemical kinetics with multiple time scales and spectral gaps.

Publications:

2011

• Dedner, A., Fein, M., Klöfkorn, R., Kröner, D., Lebiedz, D., Siehr, J., Unger, J.                                                                               On the Computation of Slow Manifolds in Chemical Kinetics via Optimization and their Use as Reduced Models in Reactive Flow Systems.
  Proceedings of the 13th International Conference on Numerical Combustion.

• Lebiedz, D., Siehr, J. Unger, J.                                                                                                                                                       A Variational Principle for Computing Slow Invariant Manifolds in Dissipative Dynamical Systems.                                                  SIAM J. Sci. Comput. 33, 703.

2010

• Lebiedz, D. Reinhardt, V., Siehr, J. Unger, J.                                                                                                                          Geometric Criteria for Model Reduction in Chemical Kinetics via Optimization of Trajectories.                                                            In "Coping with complexity: Model reduction and data analysis''.                    
  Springer Series "Lecture Notes in Computational Science and Engineering''.

• Diploma Thesis:                                                                                                                                                                          On the Analysis of an Optimization Approach to Slow Manifold Computation in Chemical Kinetics.                                       Supervisor: PD Dr. Dirk Lebiedz                                                                                                                                            File: Diplomarbeit.pdf

Teaching:

WS 2013/2014

• Dynamische Systeme und Modellreduktion

SS 2013

• Modellierung und Simulation 4

WS 2012/2013

• Angewandte Numerik 2

SS 2012

• Angewandte Numerik 1

• Optimierung mit Differenzialgleichungen

WS 2011/2012

• Mathematik für Bioinformatik und Systembiologie

SS 2011

• Profilmodul Mathematik (für Systembiologie)

SS 2010

• Einführung in Theorie und Numerik von Optimierungsproblemen

WS 2008/2009

• Mathematik I für Studierende des Ingenieurwesens und der Informatik (Tutor)

SS 2008

• Mathematik für Studierende des Ingenieurwesens II (Tutor)

WS 2007/2008

• Mathematik für Informatiker und Ingenieure I (Tutor)

Short Curriculum Vitae:

Since 04/2012

• Research associate at the Department of Numerical Mathematics, Ulm University

03/2011 - 03/2012

• Research associate at the Center for Biological Systems Analysis (ZBSA), University of Freiburg

02/2011

• Diploma in Mathematics, University of Freiburg

10/2005 - 02/2011

• Studies of Mathematics, University of Freiburg

10/2007 - 07/2010

• Student research assistant, University of Freiburg

06/2005

• Abitur, Gymnasium Bildungszentrum Weissacher Tal

05/1986

• Born in Backnang, Baden-Württemberg, Germany