TY - CHAP A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - One-Dimensional Turbulence investigation of incompressible and low Mach number variable density pipe-flow T2 - 89th Annual Meeting of the International Association of Applied Mathematics and Mechanics March 19-23, 2018 Munich, Germany, Book of abstracts Y1 - 2018 UR - http://jahrestagung.gamm-ev.de/images/2018/book_of_abstracts.pdf SP - 285 EP - 286 PB - GAMM ER - TY - CHAP A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - Application of ODT to constant volume autoignition problems T2 - 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics March 6-10, 2017 Weimar, Germany, Book of abstracts Y1 - 2017 UR - https://www.tu-ilmenau.de/fileadmin/media/analysis/trunk/170304_BoA_GAMM_2017.pdf SP - S. 360 PB - GAMM ER - TY - GEN A1 - Glawe, Christoph A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - IMEX based Multi-Scale Time Advancement in ODTLES, T2 - Zeitschrift für angewandte Mathematik und Mechanik KW - ODTLES Y1 - 2018 U6 - https://doi.org/10.1002/zamm.201800098 SN - 1521-4001 VL - 98 IS - 11 SP - 1907 EP - 1923 ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - One‐dimensional turbulence investigation of incompressible and low Mach number variable density pipe‐flow T2 - Proceedings in Applied Mathematics and Mechanics : PAMM KW - ODT KW - pipe flow Y1 - 2018 U6 - https://doi.org/10.1002/pamm.201800090 SN - 1617-7061 VL - 18 IS - 1 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 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - Application of ODT to constant volume autoignition problems T2 - Proceedings in Applied Mathematics and Mechanics N2 - The One-Dimensional Turbulence (ODT) model is applied to a constant volume configuration by means of a periodic, one-dimensional domain subject to randomized ensemble members with initial inhomogeneous temperature fields and homogeneous mass fraction profiles. The multidimensional turbulent interactions in the flow are modeled by the separate implementation of turbulent advection and the diffusion-reaction processes, neglecting the mean advection of the system. On one hand, turbulent advection is modeled by means of the eddy events defined within the framework of ODT; on the other hand, the diffusion-reaction system is solved by means of the Zero-Mach limit conservation equations discretized with a 1D Finite Volume Method (FVM). The treatment is specialized in this work to constant volume systems. Due to the inherent stiffness of the diffusion-reaction system, an operator splitting approach is also included in the formulation. Results for n-Heptane chemistry comprising the temporal evolution of the heat release rate, pressure and normalized density-weighted displacement speed are shown and compared to DNS results from Yoo et al. [Combust. Flame 158 (2011) 1727-1741], in terms of individual ensemble members and mean ensemble behavior. The results show that it is possible to obtain reasonably good results in comparison to the DNS if an appropriate set of initial conditions is used. Furthermore, it is shown that the model uncertainty is negligible in comparison to the ensemble standard deviation introduced by randomized initial conditions. Overall, this work introduces the framework for constant volume autoignition in ODT and shows its efficiency for complex chemistry simulations. Y1 - 2017 U6 - https://doi.org/10.1002/pamm.201710291 SN - 1617-7061 VL - 17 IS - 1 SP - 643 EP - 644 ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko A1 - Riebel, Ulrich T1 - Towards a One-Dimensional Turbulence Approach for Electrohydrodynamic Flows Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2019_TSFPPoster2019.pdf ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko A1 - Riebel, Ulrich T1 - Extension of the One-Dimensional Turbulence model towards electrohydrodynamic variable density flows T2 - 17th European Turbulence Conference (ETC2019), 3-6 September 2019, Torino, Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2019_ETC2019ODTEHDPlate.pdf CY - Turin 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 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko A1 - Lignell, David O. T1 - Application of the One-Dimensional Turbulence model to incompressible channel and pipe flow T2 - Publications Turbulent Reacting Flow Research Dr. David Lignell, Brigham Young University Y1 - 2019 UR - https://www.researchgate.net/publication/324604188_Application_of_the_One-Dimensional_Turbulence_model_to_incompressible_channel_and_pipe_flow/link/5ad8bda7a6fdcc29358659c4/download 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 - Bacher, Christian A1 - Riebel, Ulrich A1 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - Nutzbarmachung des elektrischen Windes zum verbesserten Wärme und Stofftransport im Elektroabscheider T2 - ProcessNet 2020, Fachgruppe Gasreinigung N2 - Zur Förderung einer nachhaltigeren Wertschöpfungskette werden im Rahmen der Energiewende ständig neue Verfahren und Konzepte zu deren Umsetzung entwickelt. Eines dieser Konzepte befasst sich mit der Zusammenführung bislang entkoppelter Prozessschritte in Gasreinigungssystemen aus der Energie- und Anlagentechnik. Aus den daraus resultierenden Einsparungen bei den Investitionskosten profitieren nicht nur die klassischen Energieerzeugeuer und Produktionsanlagen in der chemischen Industrie, sondern es werden auch neue Anreize zur dezentralen Energieeinspeisung von kleineren und mittelständischen Unternehmen gesetzt. Elementarer Bestandteil dieser Gasreinigungssysteme sind häufig Elektroabscheider, welche weit verbreitet im Einsatz sind um Abgase von Stäuben bzw. Aerosolen zu befreien, oder um staubförmige Wertprodukte aus Gasströmungen abzuscheiden. Die in Elektroabscheidern prinzipbedingt vorhandenen elektro¬¬hydro¬dyna¬mischen Strömungen, auch als elektrischer Wind bezeichnet, sollen nun systematisch genutzt werden, um neben der Aerosolabscheidung gleichzeitig Aufgaben des Wärme- und Stoffaustauschs zu lösen. Inhalte der Untersuchungen Zur Validierung der Machbarkeit dieser neuen Techniken wurde der Einfluss des elektrischen Windes auf die turbulente Quervermischung, anhand des verbesserten Wärme- und Stofftransports, sowie des Druckverlusts im Rohrelektroabscheider getestet. Bei den Untersuchungen wurden unterschiedliche Strömungsgeschwindigkeiten, Elektrodengeometrien und Betriebsspannungen, sowie die Anwesenheit von Aerosol berücksichtigt. Ein Teil der Ergebnisse diente bereits als Validierungsgrundlage für numerische Simulationen mit einem neuartigen Turbulenzmodell [1]. [1] Medina, J., Schmidt, H., Riebel, U., Application of the one-dimensional turbulence model for electrohydrodynamic variable density flows, 17th European Turbulence Conference, 3-6 September 2019, Torino, Italy Y1 - 2020 UR - https://www.researchgate.net/publication/340363119_Nutzbarmachung_des_elektrischen_Windes_zum_verbesserten_Warme-und_Stofftransport_im_Elektroabscheider ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Bacher, Christian A1 - Schmidt, Heiko A1 - Riebel, Ulrich T1 - EHD-ODT: a stochastic turbulence model for the study of heat and mass transfer in wire-tube electrostatic precipitators T2 - Jahrestreffen der ProcessNet-Fachgruppen Computational Fluid Dynamics und Gasreinigung Y1 - 2020 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2020_ProcessNETConferenceAbstract.pdf PB - DECHEMA e.V. 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 - Schmidt, Heiko T1 - The One-Dimensional Turbulence aspects of internal forced convective flows T2 - 14th World Congress on Computational Mechanics (WCCM XIV) ; 8th European Congress on Computational Methods in Applied Science and Engineering (ECCOMAS 2020) Y1 - 2020 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2020_ODTInternalForcedConvectiveFlows.pdf CY - Paris, France ER - TY - THES A1 - Medina Méndez, Juan Ali T1 - Application of the One-Dimensional Turbulence model to electrohydrodynamically enhanced internally forced convective flows N2 - This thesis is an attempt to assess some of the effects that electroquasistatic body forces exert on turbulent internally forced convective flows. In order to do that, a stochastic turbulence model is employed, namely, the One-Dimensional Turbulence (ODT) model. The reduced dimensionality of ODT demands a reduction of the Navier-Stokes equations (and in this case, also the Maxwell equations), into a 1-D system. This is done by performing an asymptotic analysis in terms of the nondimensional numbers of the flow. Also, a validation step due to the relative novel character of the cylindrical ODT formulation is done for an incompressible and constant properties flow regime and a variable density flow regime. The validation is presented for both the temporal (T-ODT) and a novel spatial (S-ODT) formulation in both planar and cylindrical geometries. Results in the constant property case show that wall normal (and radial) profiles, in both the T-ODT and S-ODT formulations, show good agreement with each other and to the data of Direct Numerical Simulations (DNSs). For the evaluated variable density heated pipe flow, gradients at the wall can be better reproduced with S-ODT. After validating the model, ODT is applied first into a planar configuration which emulates the flow in a wire-plate Electrostatic Precipitator (ESP). For this flow, the additional input energy due to the electroquasistatic body force has an effect on the modification of the bulk velocity, and subsequently, the skin friction coefficient. Some qualitative DNS trends are confirmed with ODT, such as the localized increase of the Reynolds stress, as a consequence of increased eddy activity close to the discharge electrodes. Next, the results of ODT simulations in a cylindrical wire-tube ESP are presented. Here, ODT results are compared to experimental results. ODT results for global integral quantities such as the streamwise pressure gradient and the Nusselt number enhancement ratio are able to match in a reasonable way the experimental results. The competing relevance between the EHD contribution to turbulence by momentum, and by affecting the temperature and density due to the Joule heating effect is also analyzed, showing the leading order relevance of the former one. Specifically for the Nusselt number results, the sensitivity of the EHD flow to transition effects is shown to be very significant. This thesis may open the door to a vast new field of phenomena which can not only serve for the further validation of the ODT model against DNSs or experiments, but also for the real use of ODT in applications which are so far inaccessible for traditional DNSs. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:co1-opus4-53388 UR - https://opus4.kobv.de/opus4-btu/frontdoor/index/index/docId/5338 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 - Schmidt, Heiko T1 - EHD-enhanced internal forced convection from a One-Dimensional Turbulence perspective T2 - 91st Annual Meeting of the International Association of Applied Mathematics and Mechanics March 15-19, 2021 Kassel, Germany, Book of Abstracts Y1 - 2021 UR - https://hessenbox.uni-kassel.de/dl/fiUVgdpGYRwJeGzRN2jt5n2o/bookofabstracts2021.pdf?inline SP - 363 EP - 363 PB - Universität Kassel CY - Kassel 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 - Medina Méndez, Juan Ali A1 - Schmidt, Heiko T1 - Towards the application of the One-Dimensional Turbulence model for the evaluation of collection efficiencies in wire-tube electrostatic precipitators T2 - Proceedings in Applied Mathematics and Mechanics Y1 - 2021 U6 - https://doi.org/10.1002/pamm.202100220 SN - 1617-7061 VL - 21 IS - 1 ER -