Interfaces in Turbulent Premixed Flames (ITPF)

Principal Investigator: Dr.-Ing. Luis Cifuentes

luis.cifuentes@uni-due.de

Marie Skłodowska-Curie research project (MSCA-IF-2015-EF; 706672): 2016 - 2018, Interfaces in Turbulent Premixed Flames (ITPF). Institut für Verbrennung und Gasdynamik – Lehrstuhl für Fluiddynamik, Universität Duisburg-Essen, Duisburg – Germany

This research will characterize the entrainment processes through the study and comparison of Turbulent/Non-Turbulent (T/NT) enstrophy and scalar interfaces in turbulent premixed flames. This is an essential point in combusting turbulent free shear flows, because a better knowledge of the dynamics of T/NT and scalar interfaces would lead to better predictions of flame instabilities and field structures. Moreover, the insight gained by this analysis will, in turn, be used to propose more physically sound and accurate turbulent mixing models. The entrainment mechanisms have been studied for the past decades. However, the description and quantification of the importance of small and large scales contributing to it is still unsolved. Thus, this research will use methodologies to locally characterize small-scale scalar structures and flow topologies, as well as, to scrutinize how large and medium size vortices influence and drive the entrainment processes. Therefore, this research requires high-resolution simulations to investigate the structure of the enstrophy and scalar interfaces; this research intends to develop a Direct Numerical Simulation (DNS) of a turbulent premixed flame and analyze its results, in conjunction with Large Eddy Simulations (LES). A smart combination of DNS and LES will permit to unveil contributions of large and small structures to the entrainment process, to better comprehend physical mechanisms and to formulate sound and accurate mixing and combustion models.

The data generated in this project is available to other researchers, respective queries can be addressed to the Chair of Fluid Dynamics of the University of Duisburg-Essen: www.uni-due.de/ivg/fluiddynamik/en/index_en.php.

Acknowledgments

The authors gratefully acknowledge the Gauss Centre for Supercomputing e.V. (www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC at Leibniz Supercomputing Centre (www.lrz.de) and also by providing computing time on the Jülich Supercomputing Centre (JSC). The authors gratefully acknowledge the computing time granted by the Center for Computational Sciences and Simulation (CCSS) of the Universität of Duisburg-Essen and provided on the supercomputer magnitUDE (DFG grants INST 20876/209-1 FUGG, INST 20876/243-1 FUGG) at the Zentrum für Informations- und Mediendienste (ZIM).

2018.10.09 Analysis of Flame Curvature Evolution in a Turbulent Premixed Bluff Body Burner

2018.10.09 - Cifuentes L, Dopazo C, Anurag S, Chakraborty N, Kempf A. Physics of Fluids

2018.09.28 Flame-turbulence interactions in turbulent premixed flames

2018.09.28 - Cifuentes L, Kempf A. European Researchers' Night (Poster) - Marie Skłodowska Curie Action, Kiel

2018.09.27 Mini-symposium on Flame- and Flow-Topologies (Part I and Part II)

2018.09.27 - Cifuentes L, Kempf A, Dopazo C. ERCOFTAC Symposium ETMM12, Montpellier – France

2018.09.27 Small-scale flow topologies in the neighborhood of enstrophy and scalar interfaces

2018.09.27 - Cifuentes L, Kempf A, Dopazo C. ERCOFTAC Symposium ETMM12, Montpellier – France

2018.08.23 Local entrainment velocity in a premixed turbulent annular jet flame

2018.08.23 - Cifuentes L, Kempf A, Dopazo C. Proceedings of the Combustion Institute

2018.08.01 Final report: Rigorous study of entrainment using DNS and LES of turbulent premixed jet flames

2018.08.01 - Final report: Large Scale Computing Project at the Leibniz Supercomputing Center (SuperMUC 82M core-h: 2017 - 2018). Chair of Fluid Dynamics – Universität Duisburg-Essen, Duisburg – Germany

2018.07.30 Local entrainment velocity in a premixed turbulent annular jet flame

2018.07.30 - Cifuentes L, Kempf A, Dopazo C. 37th International Symposium on Combustion – the Combustion Institute. Dublin – Ireland

2018.07.27 DNS of turbulent premixed flames: Flow and added small-scale topologies

2018.07.27 - Cifuentes L, Kempf A. Sixteenth International Workshop on Premixed Turbulent Flames PTF-16, Dublin – Ireland

2018.05.24 Flow and added small-scale topologies in a turbulent premixed flame

2018.05.24 - Cifuentes L, Kempf A, Dopazo C. Joint meeting of the German and Italian sections of the Combustion Institute, Sorrento – Italy

2017.11.14 Flow topologies and scalar field geometries across the scalar and turbulent/non-turbulent interfaces

2017.11.14 - Cifuentes L, Kempf A. Universität der Bundeswehr München

2017.09.06 Small-scale flow topologies and scalar field geometries near the enstrophy and scalar interfaces in premixed turbulent jet flames

2017.09.06 - Cifuentes L, Kempf A. Biannual meeting of the German Section of the Combustion Institute ‘Deutscher Flammentag’

2017.08.16 Small-scale flow topologies and scalar field geometries near the enstrophy and scalar interfaces

2017.08.16 - Cifuentes L, Kempf A. Chair of Fluid Dynamics – Universität Duisburg-Essen, Duisburg – Germany

2017.07.03 Numerical investigation of the enstrophy and scalar interfaces in a turbulent premixed bluff-body burner

2017.07.03 - Cifuentes L, Kempf A, Dopazo C. EUROMECH 590 Symposium on Turbulent/Non-Turbulent interfaces (2017), Imperial College London – United Kingdom

2017.05.30 Interaction of the Turbulent/Non-Turbulent interface with scalar interfaces in premixed turbulent jet flames

2017.05.30 - Cifuentes L, Proch F, Kempf A. ERCOFTAC Workshop Direct and Large-Eddy Simulation DLES11, Pisa – Italy

2017.05.09 Interactions between local flow topologies and scalar structures in turbulent premixed flames

2017.05.09 - Cifuentes L. Institut für Verbrennung und Gasdynamik – Universität Duisburg-Essen, Duisburg – Germany

2017.05.05 Vorticity budgets in premixed combusting turbulent flows at different Lewis numbers

2017.05.05 - Dopazo C, Cifuentes L, Chakraborty N. Physics of Fluids

2017.04.28 Project approval: Rigorous study of entrainment using DNS and LES of turbulent premixed jet flames

28.04.2017 - HPC granted: We have been awarded with a grant of 82 million core-hours to conduct massively parallel Direct Numerical Simulations and Large Eddy Simulations of turbulent premixed jet flames on SuperMUC at the Leibniz Supercomputing Centre. Project ID pr53fa. Coordinated by Dr.-Ing. Luis Cifuentes and Prof. Dr.-Ing. Andreas Kempf.

2017.03.08 Interfaces in Turbulent Premixed Flames – ITPF project

2017.03.08 - Cifuentes L, Kempf A. Chair of Fluid Dynamics – Universität Duisburg-Essen, Duisburg – Germany.

2017.02.20 Project submission: Rigorous study of entrainment using DNS and LES of turbulent premixed jet flames

2017.02.20 - Project submission: Large Scale Computing Project at the Leibniz Supercomputing Center (SuperMUC 82M core-h: 2017 - 2018). Chair of Fluid Dynamics – Universität Duisburg-Essen, Duisburg – Germany

Instantaneous enstrophy field, progress variable iso-lines c=0.1 and c=0.9, and iso-lines defining the enstrophy inner and outer interfaces of the Cambridge flame (Cifuentes et al. Proc. Inst. 2018).

www.dropbox.com/s/3ajkfmkdssqp3bt/Enstrophy-field.mov?dl=0

(a) Inert case - Turbulent jet in a co-flow

(www.dropbox.com/s/njm2u0x9yneuflv/Turbulent_jet_in_coflow.mov?dl=0)

(b) Reactive case - Turbulent jet in a co-flow

(www.dropbox.com/s/njm2u0x9yneuflv/Turbulent_jet_in_coflow.mov?dl=0)

(www.dropbox.com/s/px6vgbwe24ickvq/Cambridge_flame.mov?dl=0)

Three-dimensional blue iso-surface c=0.5 with gray vortical structures identified by the second invariant of the velocity-gradient tensor Q=80.

Instantaneous enstrophy at different Lewis numbers. Iso-lines of the normalized progress variable c=0.3 and c=0.95 mark the limits for the preheat and burning regions.