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Thorsten Zirwes

Thorsten Zirwes

Gebäude449
Raum295
Tel.+49 721 608-29278

E-Mailthorsten zirwesWcm4∂kit edu
Scientific Computing and Simulation
Mitarbeiter / Mitarbeiterinnen

Research

Combustion is still the most important energy source. Today, over 80 % of the world's primary energy consumption is supplied by fossil fuels [1]. In order to meet the climate goals despite the world's growing energy demands, it is important to increase the efficiency and reduce the pollutant emissions of future combustion systems. But this is only possible with a better understanding of the fundamental physical and chemical processes that underlie combustion.

An important technique for studying combustion processes is Computational Fluid Dynamics (CFD), where computers are used to perform numerical simulations. A special CFD method is the Direct Numerical Simulation (DNS). In DNS, no simplifications are used to model the complex combustion phenomena and the gas flow. Instead, the governing mathematical equations are solved directly. In order to do this, the simulation has to resolve all details that are relevant in the combustion: the (turbulent) flow field has to be resolved down to the smallest structures, which might be of the order of a few micrometers, while the computational domain my span meters. Additionally, the thin reactive layer of the flames, where most of the chemical reactions take place, has to be captured in detail as well. Detailed chemical reaction mechanisms have to be used, which can include tens of thousands of different chemical reactions for describing the combustion. This also constrains the temporal resolution of the simulations, because even the fastest reactions have to be considered.

Because of this, DNS of combustion is very computationally expensive and only possible to perform on supercomputers. We developed a DNS solver for turbulent flames in OpenFOAM [2], which uses an optimized chemistry implementation and is coupled to Cantera [3] in order to compute detailed molecular fluxes. Figure 1 shows scaling tests performed on the ForHLR II Cluster at the SCC and the Hazel Hen Cluster at the HLRS. The results were obtained with OpenFOAM v1612+ on a computational grid with 176 million cells on up to 28800 CPU cores.

Figure 1: Scaling tests with OpenFOAM v1612+.
Source: Zirwes, T.; Zhang, F.; Denev, J.A.; Habisreuther, P.; Bockhorn, H. 2017. Automated Code Generation for Maximizing Performance of Detailed Chemistry Calculations in OpenFOAM. In High Performance Computing in Science and Engineering '17. Springer International Publishing

The results of DNS are very valuable because they allow to gain deeper insights in the mutual interaction between the flame and the fluid flow field, which is still not fully unterstood [4]. DNS can also be used to investigate phenomena which are not accessible through experiments. Figure 2 shows a 2D cut of the temperature field from a DNS of a model burner ("Sydney Burner"), which generates a flame where the fuel and oxidizer are only partially premixed. Figure 3 shows the heat release rate as well as a vorticity iso-surface to illustrate the highly turbulent flow in the central jet region.

Figure 2: Temperature field of a partially premixed flame.
Figure 3: Vorticity iso-surface colored by fluid velocity and heat release rate.

 

Publications

Zirwes, T.; Zhang, F.; Denev, J.A.; Habisreuther, P.; Bockhorn, H. 2017. Automated Code Generation for Maximizing Performance of Detailed Chemistry Calculations in OpenFOAM. In High Performance Computing in Science and Engineering '17. Springer International Publishing (accepted)

Zirwes, T.; Zhang, F.; Denev, J.A.; Habisreuther, P; Bockhorn, H.; Zarzalis, N. 2017. Effect of Elevated Pressure on the Flame Response To Stretch of Premixed Flames. 28. Deutscher Flammentag, 6 September - 7 September, Darmstadt, Deutschland

Zirwes, T.; Zhang, T.; Häber, T.; Roth, T.; Bockhorn, H. 2017. Direct numerical simulation of ignition by hot moving particles. 26th International Colloquium on the Dynamics of Explosions and Reactive Systems, July 30 - August 04, Boston, USA, ICDERS2017-1121

Zirwes, T.; Zhang, F.; Denev, J.; Habisreuther, P.; Bockhorn, H.; Zarzalis, N. 2017. Response of Local and Global Consumption Speed to Stretch in Laminar Steady-State Flames. In Proceedings of the 8th European Combustion Meeting – 2017, April 18-21, Dubrovnik, Croatia, ECM2017.0379

Häber; T.; Zirwes, T; Roth, D.; Zhang, F.; Bockhorn, H.; Maas, U. 2017. Numerical Simulation of the Ignition of Fuel/Air Gas Mixtures Around Small Hot Particles. Zeitschrift für Physikalische Chemie DOI:10.1515/zpch-2016-0933

Zhang, F.; Zirwes,T.; Habisreuther, P.; Bockhorn, H. 2017. Towards Reduction of Computational Cost for Large-Scale Combustion Modeling with a Multi-Regional Concept. Progress in Computational Fluid Dynamics, accepted for publication.

Zhang, F.; Zirwes,T.; Habisreuther, P.; Bockhorn, H. 2017. Effect of unsteady stretching on the flame local dynamics. Combustion and Flame, 175, 170-179. DOI:10.1016/j.combustflame.2016.05.028

Zhang, F.; Baust, T.; Zirwes, T.; Denev , J.A.; Habisreuther, P.; Zarzalis, N.; Bockhorn, H. 2016. Impact of infinite thin flame approach on the evaluation of flame speed using spherically expanding flames. Energy Technology 5(7) p. 1055–1063, DOI:10.1002/ente.201600573

Zhang, F.; Zirwes,T.; Nawroth, H.; Habisreuther, P.; Bockhorn, H.; Paschereit, C.O. 2016. Combustion generated noise: an environment related issue for future combustion systems. Energy Technology 5(7) p. 1045 –1054, DOI:10.1002/ente.201600526

Zhang, F.; Zirwes, T.; Habisreuther, P.; Bockhorn, H. A DNS Analysis of the Evaluation of Heat Release Rates from Chemiluminescence Measurements in Turbulent Combustion. in: W.E. Nagel; D.H. Kröner; M.M. Resch. High Performance Computing in Science and Engineering '16, Springer, 2016. doi:10.1007/978-3-319-47066-5
 
For older publications, see HERE

Presentations and Posters

Zirwes, T.; Zhang, F.; Denev, J.A.; Habisreuther, P.; Bockhorn, H. 2017. Automated Code Generation for Maximizing Performance of Detailed Chemistry Calculations in OpenFOAM, 20th Results and Review Workshop of the HLRS, Oct 05 -- Oct 06, 2017, Stuttgart, Germany (Presentation)
 
Zirwes, T.; Zhang, F.; Jordan A.D.; Habisreuther, P; Bockhorn, H.; Zarzalis, N. 2017. Effect of Elevated Pressure on the Flame Response To Stretch of Premixed Flames. 28. Deutscher Flammentag , 6 Sep - 7 Sep, Darmstadt, Germany (Presentation)
 
Zirwes, T.; Zhang, F.; Häber, T.; Roth, D.; Bockhorn, H. 2017. Direct numerical simulation of ignition by hot moving particles. 26th International Colloquium on the Dynamics of Explosions and Reactive Systems, July 30 - August 04, Boston, USA (Presentation)
 
Zirwes, T.; Zhang, F.; Denev, J.; Habisreuther, P.; Bockhorn, H.; Zarzalis, N. 2017. Response of Local and Global Consumption Speed to Stretch in Laminar Steady-State Flames, in Proceedings of the European Combustion Meeting, April 18-21, Dubrovnik, Croatia (Presentation)
 
Zirwes, T.; Zhang, F.; Habisreuther, P.; Bockhorn, H. 2016. A DNS Analysis of the Correlation of Heat Release Rate with Chemiluminescence Emissions in Turbulent Combustion. The 19th Results and Review Workshop of the HLRS, October 13-14, Stuttgart, Germany (Presentation)
 
Zhang, F.; Zirwes, T.; Habisreuther, P.; Bockhorn, H.; Nawroth, H.; Paschereit, C.O. 2016. LES and DNS of Combustion and Combustion Generated Noise. 2nd Colloquium on Combustion Dynamics and Noise, September 19-22, Menaggio, Italy (Presentation)
 
Zirwes, T.; Zhang, F.; Habisreuther, P.; Bockhorn, H. 2016. Flame Response to Unsteady Stretching. 36th International Symposium on Combustion, July 31 - August 5,, Seoul, Korea (Poster)
 
For older entries see HERE