TY - CHAP A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Towards numerical simulation of the ultimate state of convection using one-dimensional turbulence modeling T2 - International Conference on Rayleigh Bénard Convection, May 14-18, Enschede, The Netherlands, abstracts Y1 - 2018 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_2018_rbc_abstract.pdf ER - TY - CHAP A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Stochastic Modeling of Passive Scalar Transport in Turbulent Channel Flows at High Schmidt Numbers T2 - 10th International Symposium on Turbulence and Shear Flow Phenomena (TSFP10), Chicago, USA, July, 2017 Y1 - 2017 UR - http://tsfp10.org/TSFP10_program/2/368.pdf ER - TY - CHAP A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating the Reynolds number dependency of the scalar transfer to a wall using a stochastic turbulence model 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 - S. 287 PB - GAMM ER - TY - CHAP A1 - Klein, Marten A1 - Schmidt, Heiko T1 - On Turbulent Scalar Transport at Very High Schmidt Numbers Using a Stochastic Modeling Appro T2 - 88th Annual Meeting of the International Association of Applied Mathematics and Mechanics March 6-10, 2017 Weimar, Germany, Book of abstacts Y1 - 2017 UR - https://www.tu-ilmenau.de/fileadmin/media/analysis/trunk/170304_BoA_GAMM_2017.pdf SP - 357 EP - 358 PB - GAMM ER - 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 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating the Reynolds number dependency of the scalar transfer to a wall using a stochastic turbulence model T2 - Proceedings in applied mathematics and mechanics : PAMM Y1 - 2018 U6 - https://doi.org/10.1002/pamm.201800238 SN - 1617-7061 VL - 18 IS - 1 ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Stochastic Modeling of Turbulent Scalar Transport at Very High Schmidt Numbers T2 - Proceedings in applied mathematics and mechanics : PAMM Y1 - 2017 UR - https://onlinelibrary.wiley.com/doi/pdf/10.1002/pamm.201710289 U6 - https://doi.org/10.1002/pamm.201710289 SN - 1617-7061 VL - 17 IS - 1 SP - 639 EP - 640 ER - TY - GEN A1 - Vincze, Miklos A1 - Fenyvesi, Nora A1 - Klein, Marten A1 - Sommeria, Joel A1 - Viboud, Samuel A1 - Ashkenazy, Yossi T1 - Evidence for wind-induced Ekman layer resonance based on rotating tank experiments T2 - EPL : a letters journal exploring the frontiers of physics N2 - The temporal variability of wind stress acting on the ocean surface may have a significant impact on the energy transfer between the surface ocean and the abyssal ocean. In particular, the surface ocean layer is expected to deepen when the wind’s frequency matches the inertial (Coriolis) frequency, through “Ekman layer resonance”. Here, we report on laboratory experiments conducted in the large circular rotating tank of the LEGI Coriolis platform (13 m in diameter and 0.5 m in depth) to investigate the effect of oscillating horizontal shear imposed at the water surface. The analysis of the flow structure by means of particle image velocimetry (PIV) reveals a resonant thickening of the top Ekman layer and a marked increase in the kinetic energy of the flow occurs when the forcing frequency coincides with the Coriolis frequency of the rotating tank. The findings are in agreement with the theoretical expectations and constitute evidence for the existence of the Ekman layer resonance (or near inertial resonance) phenomenon in an ocean-like configuration. KW - Fluid Dynamics KW - Rotating Flows KW - Resonance KW - Boundary Layer Y1 - 2019 UR - https://epljournal.edpsciences.org/articles/epl/abs/2019/04/epl19544/epl19544.html U6 - https://doi.org/10.1209/0295-5075/125/44001 SN - 1286-4854 VL - 125 IS - 4 SP - 1 EP - 7 ER - TY - GEN A1 - Klein, Marten A1 - Lignell, David O. A1 - Schmidt, Heiko T1 - Map-Based Modeling of Turbulent Convection: Application of the One-Dimensional Turbulence Model to Planar and Spherical Geometries KW - turbulent convection KW - stochastic modeling KW - boundary layer Y1 - 2018 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_poster_rbc18.pdf UR - https://www.researchgate.net/publication/325155414_Map-Based_Modeling_of_Turbulent_Convection_Application_of_the_One-Dimensional_Turbulence_Model_to_Planar_and_Spherical_Geometries ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Map-based Modeling of Turbulent Boundary Layers Subject to Rotation and Stratification KW - boundary layers KW - stochastic modeling KW - rotating flows KW - thermal convection KW - turbulence Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_poster_lesHouches19.pdf ER - TY - GEN A1 - Klein, Marten A1 - Zenker, Christian A1 - Schmidt, Heiko T1 - Small-scale resolving simulations of the turbulent mixing in confined planar jets using one-dimensional turbulence T2 - Chemical Engineering Science Y1 - 2019 SN - 0009-2509 VL - 204 SP - 186 EP - 202 ER - TY - GEN A1 - Ghasemi, Abouzar A1 - Klein, Marten A1 - Will, Andreas A1 - Harlander, Uwe T1 - Mean flow generation by an intermittently unstable boundary layer over a sloping wall T2 - Journal of Fluid Mechanics Y1 - 2018 U6 - https://doi.org/10.1017/jfm.2018.552 SN - 1750-6859 IS - vol. 853 SP - 111 EP - 149 ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating the skin friction drag across electrolytes and electrical fields using one-dimensional turbulence modeling T2 - European Drag Reduction and Flow Control Meeting, EDRFCM 2019, March 26-29 2019, Bad Herrenalb, Germany KW - electrohydrodynamic flows KW - Couette flow KW - turbulence modeling Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_2019_Klein+Schmidt_ODT_EHD_Couette_EDRFCM19.pdf UR - http://www.edrfcm.science/index.php/program SP - 1 EP - 2 ER - TY - GEN A1 - Klein, Marten A1 - Lignell, David O. A1 - Schmidt, Heiko T1 - Stochastic modeling of temperature and velocity statistics in spherical-shell convection T2 - Geophysical Research Abstracts, Vol. 21, EGU2019-2220 KW - turbulent convection KW - turbulence modeling KW - spherical shell Y1 - 2019 UR - https://meetingorganizer.copernicus.org/EGU2019/EGU2019-2220.pdf ER - TY - GEN A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Simulating neutrally and stably stratified turbulent Ekman flows with a stochastic turbulence model T2 - Proc. of the 17th European Turbulence Conference (ETC17), 3-6 September 2019, Torino, Italy KW - turbulent boundary layer KW - turbulence modeling KW - Coriolis effects KW - stratification effects Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_2019_etc.pdf UR - http://www.etc17.it/ ER - TY - GEN A1 - Sommeria, Joel A1 - Vincze, Miklos A1 - Fenyvesi, Nora A1 - Klein, Marten A1 - Viboud, Samuel A1 - Ashkenazy, Yosef T1 - Ekman layer resonance in an ocean-analog rotating tank experiment T2 - 17th European Turbulence Conference, Turin, 3 Sep 2019 - 6 Sep 2020 KW - Rotating and swirling flows KW - Circulation and currents KW - Coriolis effects Y1 - 2019 UR - http://www.etc17.it/ ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating Rayleigh-Bénard convection at low Prandtl numbers using one-dimensional turbulence modeling T2 - Proc. of the 11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), Southampton, UK, July 30 to August 2, 2019 KW - turbulent convection KW - turbulence modeling KW - low Prandtl number KW - high Rayleigh number Y1 - 2019 UR - http://www.tsfp-conference.org/proceedings/2019/14.pdf ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating thermal convection at low Prandtl numbers using one-dimensional turbulence KW - turbulent convection KW - turbulence modeling KW - low Prandtl number KW - high Rayleigh number Y1 - 2019 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Klein_2019_poster_tsfp11_evince-print.pdf N1 - Poster shown at 11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), 30 July - 2 August 2019, Southampton, UK ER - TY - GEN A1 - Klein, Marten A1 - Schmidt, Heiko T1 - The transition to the ultimate regime of thermal convection from a stochastic one-dimensional turbulence perspective T2 - arXiv KW - Rayleigh-Bénard convection KW - turbulence modeling KW - low Prandtl number KW - turbulent transitions KW - heat transfer Y1 - 2019 UR - https://arxiv.org/abs/1906.06621 SP - 1 EP - 11 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 -