Julian Koellermeier on ResearchGate

(Website of a former member, who has recently left MathCCES)

MATHCCES
Department of Mathematics
RWTH Aachen University
Schinkelstr. 2
D-52062 Aachen
Germany

Office: Rogowski building, room 328b
Phone: +49(0)241 80 98664
Email: .

• I started as PostDoc researcher in the group of Prof. Ruo Li at Peking University, China, in October 2018 with a Joint Postdoctoral Fellowship of FU Berlin and Peking University.

• Project 1: Artificial Neural Network (at FU Berlin)
• Project 2: Shallow water equations extensions (at FU Berlin)
• Project 3: Implicit Solution Techniques for Atmospheric Reentry Simulations
• Project 4: Numerical Methods for Flow Simulations

• Hyperbolic PDEs
• Numerics for non-conservative hyperbolic PDE systems
• Moment methods for rarefied gases
• Non-classical quadrature and Quadrature-based projections

By appointment. Please contact me via e-mail.

I recently started as a PostDoc in the group of Prof. Li at Peking University, Beijing, China. Before, I was PostDoc in the group of Prof. Klein at Freie Universität Berlin. I studied at RWTH Aachen University and did my PhD in Mathematics with Prof. Torrilhon.

• since 10/2018 PostDoc at Peking University
  
• 10/2017-09/2018 PostDoc at Freie Universität Berlin
  
• 7/2017 PhD in Applied Computational Mathematics at MathCCES, RWTH Aachen University
  
• 09/2013 M.Sc. in Computational Engineering Science at RWTH Aachen University
  
• 03/2012 B.Sc. in Computational Engineering Science at RWTH Aachen University

I am a member of the SIAM Student Chapter at RWTH Aachen, for more information see SIAMSC RWTH Aachen

• Mathematical Models in Science and Engineering, summer term, Peking University
• Mathematik für Geowissenschaftler II, SS 2018, FU Berlin
• Gewöhnliche Differentialgleichungen, SS 2017, RWTH Aachen University
• Mathematische Grundlagen III (CES), WS 2016/2017, RWTH Aachen University
• Analysis für Informatiker, WS 2015/2016, RWTH Aachen University
• Mathematische Grundlagen II (CES), SS 2015, RWTH Aachen University
• Mathematical Models in Science and Engineering (PDEs), SS 2014, RWTH Aachen University
  
• Mathematische Grundlagen I (CES), WS 2013/2014, RWTH Aachen University
• Mathematische Grundlagen I-V (CES), 2009-2012, student teaching assistant, RWTH Aachen University

• Analysis and Numerical Simulation of Hyperbolic Shallow Water Moment Equations, Julian Koellermeier, Marvin Rominger, submitted download preprint
• Accelerating the Convergence of Moment Models for the Boltzmann Equation Using Filters, Julian Koellermeier, Yuwei Fan, submitted download preprint
• Diagram notation for the derivation of hyperbolic moment systems, Julian Koellermeier, Yuwei Fan, submitted download preprint

• Two-Dimensional Simulation of Rarefied Gas Flows Using Quadrature-Based Moment Equations, Julian Koellermeier, Manuel Torrilhon, SIAM Multiscale Model. Simul., 16(2), 1059–1084, 2018 download
• Numerical Study of Partially Conservative Moment Equations in Kinetic Theory, J. Köllermeier, M. Torrilhon, Commun. in Comput. Phys., 21(4), p. 981-1011, 2017 download
• Numerical solution of hyperbolic moment models for the Boltzmann equation, J. Köllermeier, M. Torrilhon, Eur. J. Mech. B-Fluids, 64, p. 41-46, 2017 download
• Model Reduction of Kinetic Equations by Operator Projection, Y. Fan, J. Köllermeier, J. Li, R. Li, M. Torrilhon, J. Stat. Phys., 162(2), p. 457-486, 2016 download
• A Framework for Hyperbolic Approximation of Kinetic Equations Using Quadrature-Based Projection Methods, J. Köllermeier, R. P. Schärer, M. Torrilhon, Kinet. Relat. Mod., 5(3) p.531-549, 2014 download
• Solving a Non-Linear Partial Differential Equation for the Simulation of Tumour Oxygenation, J. Köllermeier, L. Kusch, T. Lajewski, SIAM Undergraduate Research Online, 5, p.128-147, 2012 download

• Error estimators for adaptive simulation of rarefied gases using hyperbolic moment models, J. Köllermeier, Proceedings of the 31st Symposium on Rarefied Gas Dynamics, to appear in AIP Conf. Proc., 2019 download
• Simplified Hyperbolic Moment Equations, J. Köllermeier, M. Torrilhon, In: Klingenberg C., Westdickenberg M. (eds) Theory, Numerics and Applications of Hyperbolic Problems II. HYP 2016. Springer Proceedings in Mathematics & Statistics, vol 237, 2018 download
• Shock structure simulation using hyperbolic moment models in partially-conservative form, J. Köllermeier, M. Torrilhon, Proceedings of the 30th Symposium on Rarefied Gas Dynamics, AIP Conf. Proc. 1786, 140004, 2016 download
• On new hyperbolic moment models for the Boltzmann equation, J. Köllermeier, M. Torrilhon, Conference Proceedings of the YIC GACM 2015, Publication Server of RWTH Aachen University, p.142-145, 2015 download
• Hyperbolic moment equations using quadrature-based projection methods, J. Köllermeier, M. Torrilhon, Proceedings of the 29th Symposium on Rarefied Gas Dynamics, AIP Conf. Proc. 1628, p.626-633, 2014 download

• Derivation and Numerical Solution of Hyperbolic Moment Equations for Rarefied Gas Flows, Julian Koellermeier, dissertation, RWTH Aachen University, 2017 download
• Hyperbolic Approximation of Kinetic Equations Using Quadrature-Based Projection Methods, J. Köllermeier, Master thesis, RWTH Aachen University, 2013 .
• Stochastic Particle Methods for Rarefied Gases, J. Köllermeier, seminar work, RWTH Aachen University, 2013 .
• Comparison of Time-Stepping Schemes for Compressible Gas Dynamics, J. Köllermeier, Bachelor thesis, RWTH Aachen University, 2012 .
• Implementation of Implicit Solution Techniques for Non-Equilibrium Hypersonic Flows, J. Köllermeier, von Karman Institute for Fluid Dynamics, Short Training Report 2012-04, 2012 .
• Asymptotic Accuracy for Boundary Value Problems, J. Köllermeier, M. Torrilhon, project work, RWTH Aachen University, 2011 .
• Virtual tumour project, J. Köllermeier, L. Kusch, T. Lajewski, project work, RWTH Aachen University, 2011 .

• Simulation of rarefied gases using filtered hyperbolic moment equations, invited talk, Hong Kong University of Science and Technology, Hong Kong, May 22nd, 2019 .
• Hyperbolic Regularization of Shallow Water Moment Equations, invited talk, Zhejiang University, Hangzhou, March 20th, 2019 .
• On Derivation and Analysis of Moment Models for the Shallow Water Equation, seminar talk, Peking University, March 7th, 2019 .
• Filtered Hyperbolic Moment Equations for Improved Convergence, SIAM Conference on Computational Science and Engineering, Spokane, Februar 25th, 2019 .
• Non-conservative models for rarefied gas flows: properties and numerical solution, invited talk, Universidad Malaga, February 5th, 2019 .
• Derivation and Numerical Solution of Hyperbolic Moment Equations for Rarefied Gas Flows, presentation at the annual Computational Applied Physics Meeting, Peking University, December 13th, 2018 .
• Using Projective Integration for Accelerated Computation of Stiff ODEs, invited talk, University of Science and Technology Beijing, December 11th, 2018 .
• Projective Integration for Moment Equations, seminar talk, Peking University, November 21st, 2018 .
• Filtered Hyperbolic Moment Equations, lecture, Peking University, October 23rd, 2018 .
• Hyperbolic Moment Models for Rarefied Gases: Recent Developments and Future Projects, seminar talk, Peking University, October 17th, 2018 .
• Adaptive Simulation of Rarefied Gases Using Hierarchical Moment Models, International Congress of Mathematicians, Rio de Janeiro, August 3rd, 2018 .
• Improving the Convergence of Moment Methods for Rarefied Gases Using Filters, 31st International Symposium on Rarefed Gas Dynamics, Glasgow, July 26th, 2018 .
• Accelerated convergence of moment models for the Boltzmann equation using filters, KU Leuven, Leuven, June 14th, 2018 .
• Atmospheric Reentry and Numerical Simulation of Rarefied Gases, University of Ottawa, Ottawa, March 29th, 2018 .
• Numerical simulation of rarefied gases using continuum models, Brown University, Providence, March 23rd, 2018 .
• On model adaptive simulations of rarefied gases using hyperbolic moment models, Von Karman Institute, Brussels, January 22nd, 2018 .
• Derivation and Numerical Solution of Hyperbolic Moment Equations for Rarefied Gas Flows, invited speaker at Workshop on Moment Methods in Kinetic Theory III, Peking University, September 27th, 2017 .
• Derivation and Numerical Solution of Hyperbolic Moment Equations for Rarefied Gas Flows, PhD defense, RWTH Aachen University, July 26th, 2017 .
• Numerical Simulation of Rarefied Gases using Hyperbolic Moment Equations in Partially-Conservative Form, Free University Berlin, May 18th, 2017 .
• On a New Diagram Notation for the Derivation of Hyperbolic Moment Models, Stanford University, March 17th, 2017 .
• Higher order numerical schemes for non-conservative hyperbolic PDEs on 2D unstructured grids, SIAM Conference on Computational Science and Engineering, Atlanta, March 1st, 2017 .
• Extension of standard fluid dynamics equations: Simulation of rarefied gases using hyperbolic moment models, poster presentation at SIAM Conference on Computational Science and Engineering, Atlanta, February 28th, 2017 .
• Atmospheric Entry - Technology, Mathematical Model and Simulation, SIAM Student Chapter Seminar on Applied Mathematics, RWTH Aachen University, August 26th, 2016 .
• On the Derivation and Numerical Solution of Stable Hyperbolic Moment Equations, 16th International Conference on Hyperbolic Problems, Aachen, August 1st, 2016 .
• Numerical Convergence Study of Hyperbolic Moment Models in Partially-Conservative Form, 30th International Symposium on Rarefed Gas Dynamics, Victoria, July 12th, 2016 .
• On the Stability of Hyperbolic Moment Equations, Beijing Computational Science Research Center, Beijing, May 24th, 2016 .
• Atmospheric Reentry Simulation, Berlin, April 26th, 2016 .
• Numerical Solution of Hyperbolic Moment Models for the Boltzmann Equation, 2nd European Conference on Non-equilibrium Gas Flows, TU Eindhoven, December 10th, 2015 .
• On the Stability and Numerical Solution of Partially Conservative Hyperbolic Moment Equations, lunch talk seminar at MathCCES, RWTH Aachen University, November 26th, 2015 .
• Reentry - From Science Fiction to Simulation, Bonn, November 1st, 2015 .
• Comparison of Numerical Solutions for the Boltzmann Equation and Different Moment Models, Chinese Academy of Sciences, Beijing, October 12th, 2015 .
• Numerical Solution of Hyperbolic Moment Equations for the Boltzmann Equation, Peking University, Beijing, October 8th, 2015 .
• Numerical solution of hyperbolic moment models for the Boltzmann equation in non-conservative form, poster presentation at AC.CES conference, RWTH Aachen University, July 23rd, 2015 .
• On new hyperbolic moment models for the Boltzmann equation, ECCOMAS Young Investigators Conference, RWTH Aachen University, July 21st, 2015 .
• Atmospheric Reentry - Mathematical Modelling of Rarefied Gases, Heidelberg, April 24th, 2015 .
• On the Numerical Solution of the Boltzmann Equation Using Quadrature-Based Projection Methods, poster presentation at SIAM Conference on Computational Science and Engineering, Salt Lake City, March 15th, 2015 .
• On an Operator Projection Framework for Kinetic Equations, lunch talk seminar at MathCCES, RWTH Aachen University, December 11th, 2014 .
• Quadrature-Based Moment Method for the Boltzmann Equation, poster presentation at Workshop on Moment Methods in Kinetic Theory II, Toronto, October 15th, 2014 .
• Atmospheric Reentry - Introduction, Mathematical Model and Simulation, Gummersbach, August 23rd, 2014 .
• Adaptive and Hyperbolic Quadrature-Based Moment Method for the Boltzmann Equation, Peking University, Beijing, August 18th, 2014 .
• Comparison of Hyperbolic Moment Models for the Boltzmann Equation, China Three Gorges University, Yichang, August 8th, 2014 .
• Hyperbolic Moment Equations Using Quadrature-Based Projection Methods, 29th International Symposium on Rarefed Gas Dynamics, Xi'an, July 14th, 2014 .
• Hyperbolic Approximation of Kinetic Equations Using Quadrature-Based Projection Methods, Master Thesis defense at MathCCES, RWTH Aachen University, September 25th, 2013 .
• Stochastic Particle Methods for Rarefifed Gases, seminar talk at MathCCES, RWTH Aachen University, February 1st, 2013 .
• Comparison of Time Stepping Techniques for Compressible Gas Dynamics, Bachelor Thesis defense at MathCCES, RWTH Aachen University, May 3rd, 2012 .
• Implementation of Implicit Solution Techniques for Non-equilibrium Hypersonic Flows, Internship Report at von Karman Institute, Brussels, December 15th, 2011 and at MathCCES, RWTH Aachen University, January 12th, 2012 .
• Solving a non-linear partial differential equation for the simulation of tumour oxygenation, Karolinska Institute, Stockholm, September 19th, 2011 .
• Virtual tumour project, project presentation/lunch talk at MathCCES, RWTH Aachen University, May 26th, 2011 .

• Analysis and Numerical Solution of Hyperbolic Shallow Water Moment Equations, Marvin Rominger, Master thesis, FU Berlin, January 2019
• Shallow water equations in presence of topography, Maren Casfor, seminar thesis, FU Berlin, June 2018
• A Higher-Order Finite Volume Method for Non-Conservative Equations on 2D Unstructured Quadrilateral Grids, Yannick Dueren, seminar work, RWTH Aachen University, November 2016 .
• Development and Implementation of an Algorithm for the Analysis of Loaded Filter Media, Yannick Dueren, Bachelor thesis, RWTH Aachen University, March 2016 (confidential)
• Implementation of Adaptive Time Stepping Techniques for Flow Simulations, Rachna Shetty, Bachelor thesis, BITS Pilani, India, December 2015 .
• Unstructured quad grid generation and grid management for flow simulations, Laurin Scholz, Bachelor thesis, RWTH Aachen University, October 2014 .