TY - GEN A1 - Lignell, David O. A1 - Lansinger, Victoria B. A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Kerstein, Alan R. A1 - Schmidt, Heiko A1 - Fistler, Marco A1 - Oevermann, Michael T1 - One-dimensional turbulence modeling for cylindrical and spherical flows: model formulation and application T2 - Theoretical and Computational Fluid Dynamics N2 - The one-dimensional turbulence (ODT) model resolves a full range of time and length scales and is computationally efficient. ODT has been applied to a wide range of complex multi-scale flows, such as turbulent combustion. Previous ODT comparisons to experimental data have focused mainly on planar flows. Applications to cylindrical flows, such as round jets, have been based on rough analogies, e.g., by exploiting the fortuitous consistency of the similarity scalings of temporally developing planar jets and spatially developing round jets. To obtain a more systematic treatment, a new formulation of the ODT model in cylindrical and spherical coordinates is presented here. The model is written in terms of a geometric factor so that planar, cylindrical, and spherical configurations are represented in the same way. Temporal and spatial versions of the model are presented. A Lagrangian finite-volume implementation is used with a dynamically adaptive mesh. The adaptive mesh facilitates the implementation of cylindrical and spherical versions of the triplet map, which is used to model turbulent advection (eddy events) in the one-dimensional flow coordinate. In cylindrical and spherical coordinates, geometric stretching of the three triplet map images occurs due to the radial dependence of volume, with the stretching being strongest near the centerline. Two triplet map variants, TMA and TMB, are presented. In TMA, the three map images have the same volume, but different radial segment lengths. In TMB, the three map images have the same radial segment lengths, but different segment volumes. Cylindrical results are presented for temporal pipe flow, a spatial nonreacting jet, and a spatial nonreacting jet flame. These results compare very well to direct numerical simulation for the pipe flow, and to experimental data for the jets. The nonreacting jet treatment overpredicts velocity fluctuations near the centerline, due to the geometric stretching of the triplet maps and its effect on the eddy event rate distribution. TMB performs better than TMA. A hybrid planar-TMB (PTMB) approach is also presented, which further improves the results. TMA, TMB, and PTMB are nearly identical in the pipe flow where the key dynamics occur near the wall away from the centerline. The jet flame illustrates effects of variable density and viscosity, including dilatational effects. KW - Cylindrical ODT Y1 - 2018 U6 - https://doi.org/10.1007/s00162-018-0465-1 SN - 0935-4964 SN - 1432-2250 VL - 32 IS - 4 SP - 495 EP - 520 ER - TY - GEN A1 - Rakhi, Rakhi A1 - Klein, Marten A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - One-dimensional turbulence modelling of incompressible temporally developing turbulent boundary layers with comparison to DNS T2 - Journal of Turbulence N2 - The incompressible temporally developing turbulent boundary layer (TBL) is analysed using the map-based stochastic one-dimensional turbulence (ODT) model. The TBL is a canonical flow problem, which is, in the present study, formed by a planar moving wall and a free stream at rest. An understanding of this idealised flow is of fundamental relevance for the numerical analysis of turbulent boundary-layer-type flows. In the present ODT simulations, the flow variables are resolved on all scales along a wall-normal, one-dimensional domain. These variables are evolved by a deterministic and a stochastic process. The latter models the effect of turbulent advection and pressure fluctuations, whereas the former represents molecular diffusion. The model is appropriate for high Reynolds numbers for which the turbulence field exhibits a broad range of scales and is notionally featureless. We show that ODT is able to capture salient features of the TBL by comparing the various statistics with available reference direct numerical simulation (DNS) results for different bulk Reynolds numbers in the range 250 ≤ Reb ≤ 2000 using fixed model parameters. The influence of the model parameters is analysed for Reb = 1000 and optimal parameter values are provided. The results discussed in this paper suggest that ODT is an economical and reasonably accurate approach for the simulation of transient turbulent boundary-layer-type flows. KW - one-dimensional turbulence KW - stochastic modeling KW - turbulent boundary layers Y1 - 2019 U6 - https://doi.org/10.1080/14685248.2019.1674859 SN - 1468-5248 VL - 20 IS - 8 SP - 506 EP - 543 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 - Klein, Marten A1 - Schmidt, Heiko T1 - One-Dimensional Turbulence investigation of variable density effects due to heat transfer in a low Mach number internal air flow T2 - International Journal of Heat and Fluid Flow N2 - A novel spatial formulation of the One-Dimensional Turbulence (ODT) model is applied to a vertical pipe-flow with heat transfer, analogous to the Direct Numerical Simulation (DNS) performed by Bae et al. [Phys. Fluids 18, (075102) (2006)]. The framework presented here is an extension for radially confined domains of the cylindrical ODT spatial formulation for low Mach number flows with variable density. The variable density simulations for air (Prandtl number Pr = 0.71) are performed at an initial bulk Reynolds number Reb (DNS) = 6000 and Grashof number Gr (DNS) = 6.78*10^6. ODT results are presented for both the spatial formulation introduced in this work and the standard temporal formulation for cylindrical flows introduced by Lignell et al. [Theor. Comput. Fluid Dyn. 32, 4 (2018), pp. 495–520]. Streamwise bulk profiles and radial profiles at specific streamwise positions for the temporal and spatial formulations are in good agreement with the DNS results from Bae et al. For the present application, the spatial formulation yields physically better results in comparison to the temporal formulation. Overall, the findings in the original work of Bae et al. were corroborated with ODT. Although the framework proposed in this work is not a compressible framework and has some clear limitations regarding conservation properties, we suggest its use for future studies in the low Mach number variable density regime. Y1 - 2019 UR - http://www.sciencedirect.com/science/article/pii/S0142727X19301596 U6 - https://doi.org/10.1016/j.ijheatfluidflow.2019.108481 SN - 0142-727X SN - 1879-2278 VL - 80 ER - TY - GEN A1 - Schmidt, Heiko A1 - Medina Méndez, Juan Ali A1 - Klein, Marten T1 - EHD turbulence in channel flows with inhomogeneous electrical fields: a one-dimensional turbulence study T2 - 14th World Congress on Computational Mechanics (WCCM) ; ECCOMAS Congress 2020, 19–24 July 2020, Paris, France KW - EHD turbulence; channel flow; electrolyte flow; electrostatic precipitator; one-dimensional turbulence; stochastic modeling Y1 - 2020 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Schmidt_2020_EHD-channel-flows_WCCM-abstract.pdf UR - https://slideslive.com/38946214 U6 - https://doi.org/10.23967/wccm-eccomas.2020.131 ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Map-based stochastic methods for accurate modeling of turbulent transport: towards poly-dispersed engineering flows T2 - Jahrestreffen der ProcessNet Fachgruppen Mehrphasenstömung (MPH) und Computational Fluid Dynamics (CFD) Y1 - 2021 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2020_ODTProcessNet2021.pdf CY - Cottbus ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Schmidt, Heiko T1 - The One-Dimensional Turbulence Aspects of Internal Forced Convective Flows T2 - 14th WCCM-ECCOMAS Congress 2020 N2 - We present an overview of issues for the modeling of internal forced convective flows with the One-Dimensional Turbulence (ODT) model. Results of recent research as well as prospective research issues are presented for statistically streamwise homogeneous flows and streamwise inhomogeneous mixed convective flows. The results illustrate the capabilities of the model to evaluate and bring insight into a wide range of physical phenomena in the field of convective flows. Nonetheless, as a model, ODT is best suited for the evaluation of asymptotically turbulent flows, i.e., away from laminar regimes. KW - one-dimensional turbulence KW - stochastic turbulence modeling KW - turbulent drag KW - internal flow KW - heat transfer Y1 - 2021 UR - https://www.scipedia.com/public/Mendez_et_al_2021a U6 - https://doi.org/10.23967/wccm-eccomas.2020.338 SP - 1 EP - 12 PB - Scipedia ER - TY - GEN A1 - Klein, Marten A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Modeling electrohydrodynamically enhanced drag in channel and pipe flows using one-dimensional turbulence T2 - Conference on Modelling Fluid Flow (CMFF’22) KW - stochastic modeling KW - one-dimensional turbulence KW - turbulent drag enhancement KW - electrohydrodynamic turbulence KW - multiphysical boundary layers Y1 - 2022 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_cmff22_abstract_EHDdrag.pdf UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_cmff22_paper_submitted_EHDdrag.pdf UR - https://www.cmff.hu/pdf/FinalProgramme.pdf SP - 1 EP - 8 CY - Budapest, Hungary ER - TY - GEN A1 - Klein, Marten A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko ED - Vad, Janos T1 - Modeling electrohydrodynamically enhanced drag in channel and pipe flows using One-Dimensional Turbulenc T2 - Proceedings of the Conference on Modelling Fluid Flow (CMFF’22) N2 - The joint modeling of flow hydrodynamics and electrokinetics is a relatively unexplored area of turbulent flow research. We address a lack of available models for electrohydrodynamic (EHD) turbulent flow utilizing a lower-order approach, the stochastic One-Dimensional Turbulence (ODT) model. ODT is constructed on the principles of the direct energy cascade of Navier–Stokes turbulence, with key emphasis on the accurate resolution of the small molecular transport scales within a notional line-of-sight. We investigate two canonical flow configurations to demonstrate the applicability of the model in the simulation of EHD flows. First, we investigate EHD effects in zero-pressure-gradient turbulent boundary layers by two-way coupled model application to plane Couette flow of a dilute electrolyte. Second, we apply the one-way coupled model to EHD-enhanced gas flow through a vertical pipe with an inner concentric electrode, where electric fields are generated by means of a corona discharge and the corresponding effect of a continuum ionic charge density field. KW - EHD turbulence KW - multiphysical boundary layers KW - one-dimensional turbulence KW - stochastic modeling KW - turbulent drag enhancement Y1 - 2022 UR - https://www.cmff.hu/pdf/CMFF22_Conference_Proceedings.pdf UR - https://www.cmff.hu/papers/CMFF22_Final_Paper_PDF_15.pdf SN - 978-963-421-881-4 SP - 82 EP - 91 PB - University of Technology and Economics, Department of Fluid Mechanics CY - Budapest, Hungary ER - TY - GEN A1 - Medina Méndez, Juan Alí A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Fractal roughness representation in a stochastic one-dimensional turbulence modeling approach T2 - Book of Abstracts 13th International Symposium on Turbulence and Shear Flow Phenomena (TSFP13), Montréal, Canada, June 25-28, 2024 Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2024_TSFP13_Roughness_PFA_ODT.pdf CY - Montréal, Canada ER - TY - GEN A1 - Naik Burye, Nishidh Shailesh A1 - Medina Méndez, Juan Alí A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Revisiting near-wall modeling of fully developed turbulent flow in concentric annuli T2 - Jahresbericht 2024 zum 24. DGLR-Fachsymposium der STAB 13.-14. November 2024, Regensburg Y1 - 2024 UR - http://bfm.rcbe.de/files/2024/11/2024_STAB-Jahresbericht.pdf SP - 174 EP - 175 PB - Deutsche Strömungsmechanische Arbeitsgemeinschaft, STAB CY - Regensburg ER - TY - GEN A1 - Joshi, Abhishek A1 - Medina Mendez, Juan Ali A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Simulating homogenous isotropic turbulence with deterministic and stochastic forcings using a one-dimensional turbulence model N2 - To understand the intermittency present in scalar fields we need to address the expense of current start-of-art DNS to probe the higher-order structure functions. These higher order moments become increasingly sensitive to increasing Reλ and much more prone to extreme events. Here, in this work, we investigate using a Reduced order model(ODT) to simulate Homogenous Isotropic turbulence as an initial step towards that goal by employing a linear forcing [1] proposed by Lundgren that is proportional to local and instantaneous velocity. Y1 - 2024 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Joshi_2024_MFM_Poster.pdf ER -