Stefanie Günther

 

Chair for Scientific Computing
TU Kaiserslautern Bldg/Geb 34, Paul-Ehrlich-Strasse
67663 Kaiserslautern, Germany

Office:  36-409
Phone: +49 (0)631 205 5637
Fax:   +49 (0)631 205 3056
Email:   stefanie.guenther@scicomp.uni-kl.de

About Me


After my studies of mathematics with minor subject computer science at University of Trier, I am now a research assistant in the Scientific Computing group of Prof. Gauger at TU Kaiserslautern and a PhD student at RWTH Aachen University. Furthermore, I am an associated fellow at the Aachen Institute of Advanced Study in Computational Engineering Science (AICES) and an active member of the SIAM Student Chapter Aachen.

Research Interests

I am focusing on the simultaneous One-shot method for solving PDE-constrained optimization problems. The method has proven to be very efficient for optimization with steady-state PDEs. However, it’s application to unsteady PDEs in aerodynamic context is challenging and is the topic of my PhD thesis. A special focus is on optimization with turbulent, i.e. chaotic dynamics. Here, a regularization is needed for computing meaningful sensitivities of the output quantities. This leads to the so-called Least Squares Shadowing problem – a minimization problem that has to be solved in the space-time domain. Most recently, I also got interested in parallel-in-time One-shot optimization. I am currently developing an adjoint solver for the multigrid in time integration library XBraid that enables efficient sensitivity computation for unsteady PDEs on multiple processors. It’s usage in a One-shot optimization framework has great potential for speeding up the optimization process with unsteady dynamics.

In short:

  • Simultaneous One-Shot Optimization with unsteady PDEs
  • Optimal control of unsteady flows
  • Discrete and continuous adjoint method for sensitivity computation of steady and unsteady PDEs
  • One-shot optimization with chaotic dynamics
  • Parallel-in-Time optimization with unsteady PDE

Publications


2017

S. Günther, N.R. Gauger, Q. Wang (2017): A framework for simultaneous aerodynamic design optimization in the presence of chaos. In: Journal of Computational Physics, 328 pp. 387-398, 2017, (DOI 10.1016/j.jcp.2016.10.043). (Type: Article | Links | BibTeX)

2016

S. Günther, N.R. Gauger, Q. Wang (2016): Simultaneous One-shot optimization with unsteady PDEs. In: Journal of Computational and Applied Mathematics, (294), pp. 12-22, 2016, (arXiv preprint http://arxiv.org/pdf/1503.00884v1.pdf). (Type: Article | Links | BibTeX)

2015

S. Günther, N.R. Gauger, Q. Wang (2015): Extension of the One-Shot Method for Optimal Control with Unsteady PDEs. In: Computational Methods in Applied Sciences, 36 pp. 127-142, 2015. (Type: Article | BibTeX)

2014

T. Bosse, N.R. Gauger, A. Griewank, S. Günther, V. Schulz (2014): One-Shot Approaches to Design Optimzation. In: International Series of Numerical Mathematics, 165 pp. 43-66, 2014, (DOI:10. 1007/978-3-319-05083-6_5). (Type: Article | BibTeX)
T. Bosse, N.R. Gauger, A. Griewank, S. Günther, L. Kaland, et al. (2014): Optimal Design with Bounded Retardation for Problems with Non-separable Adjoints. In: International Series of Numerical Mathematics, 165 pp. 67–84, 2014, (DOI:10. 1007/978-3-319-05083-6_6). (Type: Article | BibTeX)

Talks


  • S. Günther, N.R. Gauger, J.B. Schroder, Q. Wang: Simultaneous Parallel-in-Time Optimization with Unsteady PDEs, SIAM CSE Conference, Feb 2017, Atlanta, USA
  • S. Günther, N.R. Gauger, J.B. Schroder: Adjoint Sensitivity Computation for the Parallel Multigrid Reduction in Time Software Library XBraid, 5th Workshop on Parallel-in-Time Integration, Nov 2016, Banff, Canada
  • S. Günther, N.R. Gauger, Q. Wang: Simultaneous PDE-constrained Optimization in Chaotic Dynamics – A framework for optimal control of highly separated flows, GAMM Annual Meeting, March 2016, Braunschweig, Germany
  • S. Günther, N.R. Gauger, Q. Wang: Fixed-Point Iterations for Simultaneous One-Shot Optimization of Unsteady Flows, SIAM CSE 2015, March 14-18, Salt Lake City, USA
  • S. Günther, N.R. Gauger, Q. Wang: Towards Efficient One-Shot Optimization with Unsteady Navier-Stokes Equations, GAMM 2014, March 10-14 2014, Erlangen, Germany
  • S. Günther, N.R. Gauger, Q. Wang: Extension of the One-Shot Method for Optimal Control with Unsteady PDEs, EUROGEN 2013, October 7-10 2013, Las Palmas de Gran Canaria, Spain
  • S.Günther, N.R. Gauger: One-Shot Optimization with unsteady PDE constraints, Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, March 04 2014, Cambridge, USA
  • S. Günther, E. Özkaya, A. Nemili, N.R. Gauger: Optimal Active Separation Control on Airfoils using Discrete Adjoint Approach, SIAM CSE 2013, February 25 – March 1 2013, Boston, USA