TY - CHAP A1 - Starick, Tommy A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - One-Dimensional Turbulence simulations for reactive flows in open and closed systems T2 - Conference on Modelling Fluid Flow (CMFF’18), The 17th International Conference on Fluid Flow Technologies Budapest, Hungary, September 4-7, 2018 N2 - The One-Dimensional Turbulence (ODT) model is applied to reactive flows in open and closed systems represented by a lifted jet flame in a vitiated coflow, and a constant volume autoignition configuration, respectively. ODT is a one-dimensional model for turbulent flow simulations, which uses a stochastic formulation to represent the effcts of turbulent advection. Diffusion and reaction effcts along the ODT domain are considered by deterministic evolution equations. This work is an effort to verify the applicability and effiency of the model for open and closed systems. In the open system case, ODT results are compared against experimental results of a lifted methane/air jet flame detailed in the work of Cabra et al. [1]. In the closed system case, a periodic, constant volume domain is used to investigate the sensitivity of the ignition evolution to initial temperature and composition inhomogeneities of a lean n-heptane/air mixture. In the latter context, ODT results are compared to DNS results from Luong et al. [2]. Results for the jet and constant volume configuration show a reasonable match with the experimental and DNS data, considering the reduced order of the model and the underlying assumptions for each case. At the jet configuration, a dependence of the flame evolution on the turbulence intensity parameter can be seen. For the closed system, initial temperature and composition inhomogeneities allow a mitigation of the undesirable rapid pressure rise. Y1 - 2018 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Starick_2018_cmff_final_after_review.pdf ER - TY - GEN A1 - Starick, Tommy A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - One-Dimensional Turbulence simulations for reactive flows in open and closed systems T2 - Technische Mechanik Y1 - 2019 U6 - https://doi.org/10.24352/UB.OVGU-2019-015 VL - 39 IS - 1 SP - 162 EP - 174 ER - TY - CHAP A1 - Medina Méndez, Juan Ali A1 - Glawe, Christoph A1 - Starick, Tommy A1 - Schöps, Mark Simon A1 - Schmidt, Heiko T1 - IMEX-ODTLES: A multi-scale and stochastic approach for highly turbulent flows T2 - 90th Annual Meeting of the International Association of Applied Mathematics and Mechanics February 18-22, 2019 Vienna, Austria, Abstract book Y1 - 2019 UR - https://jahrestagung.gamm-ev.de/images/2019/Photos/GAMM2019_BookofAbstracts.pdf SN - 978-3-903024-84-7 PB - TU-Verlag CY - Wien ER - TY - GEN A1 - Starick, Tommy A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - Towards a dynamic model adaptive combustion closure using LEM, ODT, and HiPS T2 - 17th International Conference on Numerical Combustion, May 6-8, 2019, Aachen, Germany, Book of Abstracts N2 - The computational cost of Direct Numerical Simulations (DNS) that resolve all scales rises with the cube of the Reynolds numberand is currently not feasible for real world applications. Large Eddy Simulations (LES) overcome this limitation by only resolving the large scale effects and completely model the small scaleeffects. This results in a strong dependence of the accuracy onthe chosen subgrid-scale model. The model adaptivity concept discussed in [Schmidt et al., ICDERS, 2007] dynamically uses different Linear Eddy Model (LEM) types [Kerstein, LEM, 1988] for stochastic closure to model the turbulent flame speed of apremixed flame within LES. In the talk, we will first summarize the progress of our group on One Dimensional Turbulence (ODT) [Kerstein, ODT, 1999] and Hierarchical Parcel Swapping (HiPS) [Kerstein, HiPS, 2013] based on reactive stand-alone simulations, [Jozefik et al., Combust. Flame, 2015] [Jozefik et al., Combust. Flame, 2016] [Medina et al., Combust. Flame, 2018]. Second,we will sketch a possible combination of the model adaptivity concept [Schmidt et al., ICDERS, 2007] and recent efficient ODTLES implementations [Glawe et al., Z. Angew. Math. Mech.,2018] to dynamically use LEM, ODT and HIPS together inside ofLES solvers to simulate turbulent reactive flows. Y1 - 2019 UR - https://nc19.itv.rwth-aachen.de/bookOfAbstracts.pdf SP - 143 EP - 144 CY - Aachen ER - TY - GEN A1 - Starick, Tommy A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Jozefik, Zoltan A1 - Schmidt, Heiko T1 - Zur jüngsten Entwicklung in der Modellierung von turbulenten Verbrennungsprozessen mittels ODT T2 - 29. Deutscher Flammentag, 17-18 September 2019, Bochum, DE N2 - Die vorliegende Arbeit befasst sich mit den jüngsten Entwicklungen und Anwendungen des One-Dimensional Turbulence (ODT) Modells auf reaktive Strömungen. Bei ODT handelt es sich um ein stochastisches und abbildungsbasiertes Turbulenzmodell zur Simulation von turbulenten Strömungen. In ODT wird das eindimensionale Rechengebiet als gedachte Linie durch das dreidimensionale Strömungsfeld verstanden, welches in Richtung des mittleren Gradienten einer Geschwindigkeit oder anderer skalarer Felder orientiert ist. Die Besonderheit von ODT liegt in der Modellierung der turbulenten Advektion durch stochastisch auftretende Wirbelereignisse. Die molekulare Diffusion und Reaktionskinetik entlang des ODT-Rechengebietes wird mittels sich zeitlich entwickelnder, deterministischer Erhaltungsgleichungen berücksichtigt und vollständig aufgelöst. In dieser Arbeit werden vorläufige ODT-Simulationsergebnisse von reaktiven Strömungen für jeweilsein offenes und ein geschlossenes System vorgestellt. Essentielle Vorarbeiten, die die Vermischungeines passiven Skalars in einer planaren Strahldüse untersuchen, werden ebenfalls gezeigt. Beim offenen System handelt es sich um eine Methan/Luft Freistrahl-Flamme in einer umgebenden Strömung aus heißen Verbrennungsgasen. Die Simulationsergebnisse werden zu Vergleichszweckenden Messungen von Cabra et al. gegenübergestellt. Beim geschlossenen System wird die Selbstzündung von mageren n-Heptan Gemischen bei niedrigen Temperaturen und komplexer Reaktionskinetik betrachtet. Hierbei werden die ODT-Ergebnisse mit den Resultaten aus einer Direkten Numerischen Simulation (DNS) verglichen. In den durchgeführten Studien konnte gezeigt werden, dass die mittels ODT erzeugten Statistiken eine beachtlich gute Übereinstimmung mit den Vergleichsdaten aufweisen. Im Hinblick auf die reduzierte Dimensionalität von ODT, die Qualitätder erzielten Ergebnisse und die erforderliche Rechenleistung, stellt ODT ein attraktives Modell zurSimulation von turbulenten und reaktiven Strömungen dar. KW - One-Dimensional Turbulence (ODT) , reaktive Strömungen Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Starick_Abstract_Flammentag_19.pdf UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Starick_2019_Flammentag19_Starick_Paper.pdf UR - http://www.leat.rub.de/index.php?do=Flammentag.html ER - TY - GEN A1 - Starick, Tommy A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Jozefik, Zoltan A1 - Schmidt, Heiko T1 - Zur jüngsten Entwicklung in der Modellierung von turbulenten Verbrennungsprozessen mittels ODT Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Starick_2019_Flammentag19_Starick_Poster.pdf ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Glawe, Christoph A1 - Starick, Tommy A1 - Schöps, Mark Simon A1 - Schmidt, Heiko T1 - IMEX-ODTLES: A multi-scale and stochastic approach for highly turbulent flows T2 - Proceedings in Applied Mathematics and Mechanics N2 - The stochastic One-Dimensional Turbulence (ODT) model is used in combination with a Large Eddy Simulation (LES) approach in order to illustrate the potential of the fully coupled model (ODTLES) for highly turbulent flows. In this work, we use a new C++ implementation of the ODTLES code in order to analyze the computational performance in a classical incompressible turbulent channel flow problem. The parallelization potential of the model, as well as its physical and numerical consistency are evaluated and compared to Direct Numerical Simulations (DNSs). The numerical results show that the model is capable of reproducing a representative part of the DNS data at a cheaper computational cost. This advantage can be enhanced in the future by the implementation of a straightforward parallelization approach. Y1 - 2019 U6 - https://doi.org/10.1002/pamm.201900433 SN - 1617-7061 VL - 19 IS - 1 ER - TY - GEN A1 - Klein, Marten A1 - Starick, Tommy A1 - Zenker, Christian A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Reduced order stochastic modeling of turbulent mixing based on conservative baker’s maps T2 - Proceedings of the 14th International ERCOFTAC Symposium on Engineering Turbulence Modelling and Measurements (ETMM-14) N2 - The detailed numerical representation of turbulent mixing processes is a standing challenge for non-premixed chemically reacting flows. The full range of relevant flow scales needs to be captured and it is also necessary to distinguish turbulent advective from molecular diffusive processes in order to represent Reynolds and Schmidt number effects. These requirements are addressed here by utilizing two different map-based stochastic turbulence modeling strategies. The one-dimensional turbulence (ODT) model utilizes event-based turbulence modeling, whereas the hierarchical parcel-swapping (HiPS) model is a fully event-based mixing model. ODT provides full-scale resolution at affordable costs by dimensional model reduction based on the boundary-layer approximation to shear flow. HiPS is far less costly than ODT but currently limited to locally homogeneous isotropic turbulence. The physics-compatible modeling capabilities with respect to phase-space representation of turbulent mixing are demonstrated for two canonical cases using standalone model formulations. KW - turbulent mixing KW - one-dimensional turbulence (ODT) KW - hierarchical parcel swapping (HiPS) KW - stochastic turbulence modeling KW - round jet KW - passive scalar Y1 - 2023 UR - https://etmm.ercoftac.org/etmm/program/conference-program/ UR - https://drive.google.com/file/d/1q2BDOO5bXfqq0Y4z4HCGndiFI033bPyg/view?usp=drive_link SP - 613 EP - 618 PB - ERCOFTAC CY - Barcelona, Spain ER -