TY - GEN A1 - Klein, Marten A1 - Schöps, Mark Simon A1 - Medina Méndez, Juan Alí A1 - Schmidt, Heiko T1 - Numerical simulation and analysis of transient Ekman boundary layers using a stochastic turbulence model T2 - EGU General Assembly 2023 KW - stochastic modeling KW - one-dimensional turbulence KW - turbulent Ekman flow KW - transient boundary layer Y1 - 2023 UR - https://meetingorganizer.copernicus.org/EGU23/EGU23-9116.html U6 - https://doi.org/10.5194/egusphere-egu23-9116 PB - EGU - European Geophysical Union CY - Vienna, Austria ER - TY - GEN A1 - Glawe, Christoph A1 - Klein, Marten A1 - Schmidt, Heiko T1 - ODT augmented RaNS T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - turbulence modeling KW - one-dimensional turbulence KW - Reynolds-averaged Navier-Stokes simulation KW - boundary layer KW - stochastic post-processing Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 368 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Medina Méndez, Juan Alí A1 - Sharma, Sparsh A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Towards the use of a reduced order and stochastic turbulence model for assessment of far-field sound radiation: low Mach number jet flows T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - turbulent noise sources KW - reduced-order modeling KW - one-dimensional turbulence KW - turbulent jet KW - stochastic modeling and simulation Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 413 EP - 414 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Sharma, Sparsh A1 - Ayton, Lorna A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Estimation of ODT-resolved acoustic sources in high Reynolds number turbulent jets T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - stochastic modeling KW - turbulent jet KW - turbulent acoustic sources KW - noise modeling KW - one-dimensional turbulence Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 414 EP - 415 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Polasanapalli, Sai Ravi Gupta A1 - Klein, Marten A1 - Schmidt, Heiko T1 - SGS modeling in lattice Boltzmann method for non-fully resolved turbulent flows T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - lattice Boltzmann method KW - subgrid-scale modeling KW - model comparison KW - thermal convection Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 363 EP - 364 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Tsai, Pei-Yun A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Effects of Reynolds number on turbulent concentric coaxial pipe flow using stochastic modeling T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics KW - spanwise wall curvature KW - turbulent pipe flow KW - stochastic modeling KW - boundary layer theory KW - one-dimensional turbulence Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 365 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Klein, Marten T1 - Map-based stochastic modeling of multiscale transfer processes in turbulent flows T2 - Book of Abstracts of the 93rd Annual Meeting of the International Association of Applied Mathematics and Mechanics N2 - The detailed modeling of turbulent mixing has remained a numerical challenge for a number of applications, ranging from chemically reacting flows to noise prediction in technical flows, and encompassing convection on multiple scales in the geophysical context, among others. Complications arise from the dynamical complexity of turbulence that manifests itself by emergent small-scale flow features, scaling cascades, and intermittency due to prescribed forcings, boundary and initial conditions. In order to robustly predict, for example, the occurrence of catalytic reactions, generation of mixing noise, or the heat transfer across a layer of fluid, it is crucial to represent the physical redistribution processes in the flow with a proper account of participating time and length scales. This yields scale-locality and causality constraints that can usually only be fully addressed by direct numerical simulation (DNS) based on the discretized three-dimensional (3-D) Navier-Stokes equations, which is a very costly undertaking and limited to moderate or low turbulence intensities. In order to over- come the fundamental limitations of statistical turbulence models and numerical cost of DNS, so-called map-based stochastic turbulence models have been developed and increasingly applied to various mutiphysical flows over the last couple of decades. These models utilize onedimensional (1-D) generalized Baker’s maps in order to distinguish advective filamentation from molecular diffusion processes, resolving all relevant scales of the flow along a single physical coordinate. Baker’s maps are probabilistically sampled with respect to size, location, and time of occurrence which introduces dynamical complexity into the bottom-up modeling approach. When the sampling is based on the evolving flow state, a self-contained reduced- order model with predictive capabilities for turbulent flows can be formulated. In the talk, I will summarize the map-based stochastic modeling strategy with an emphasize on the so-called One-Dimensional Turbulence (ODT) model. After that, I will discuss some recent advances in the field, demonstrating the applicability of the approach across flow configurations. I will address in more detail the flow physics representation by means of entrainment and passive scalar mixing in turbulent jets, as well as heat flux and wall shear stress fluctuations in heated channels and stably-stratified atmospheric boundary layers. KW - stochastic modeling KW - one-dimensional turbulence KW - heat and mass transfer KW - boundary layer KW - turbulent mixing Y1 - 2023 UR - https://jahrestagung.gamm-ev.de/wp-content/uploads/2023/05/20230517_BookofAbstracts_final_red.pdf SP - 362 PB - GAMM e.V. CY - Dresden ER - TY - GEN A1 - Glawe, Christoph A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Stochastic deconvolution of wall statistics in Reynolds-averaged Navier–Stokes simulations based on one-dimensional turbulence T2 - Proceedings in applied mathematics and mechanics : PAMM N2 - Reynolds-averaged Navier–Stokes simulation (RaNS) is state-of-the-art for numerical analysis of complex flows at high Reynolds number. Standalone RaNS may yield a reasonable estimate of the wall-shear stress and turbulent drag if a proper wall-function is prescribed, but detailed turbulence statistics cannot be obtained, especially at the wall. This lack in modeling is addressed here by a stochastic deconvolution strategy based on a stochastic one-dimensional turbulence (ODT) model. Here, a one-way coupling strategy is proposed in which a forcing term is computed from the balanced RaNS solution that is in turn utilized in the ODT model. The temporally developing ODT solution exhibits turbulent perturbations but relaxes toward the local RaNS solution due to resolved molecular-diffusive processes. It is demonstrated that the approach is able to recover the distribution of positive wall-shear stress fluctuations in turbulent channel flow. When formulated as post-processing tool, it is suggested that RaNS can be enhanced by ODT providing economical means for local high-fidelity numerical modeling based on a low-fidelity flow solution. KW - stochastic deconvolution KW - Reynolds-averaged Navier-Stokes simulation (RANS) KW - turbulent channel flow KW - turbulent boundary layer KW - one-dimensional turbulence Y1 - 2023 U6 - https://doi.org/10.1002/pamm.202300055 SN - 1617-7061 VL - 23 IS - 3 ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Klein, Marten A1 - Schmidt, Heiko T1 - Investigating dissipative roughness effects on turbulent drag using a stochastic turbulence model T2 - 18th European Turbulence Conference (ETC18), 4-6 September 2023, Valencia Y1 - 2023 UR - https://www-docs.b-tu.de/fg-stroemungsmodellierung/public/Medina_2023_Abstract_ETC18_Roughness.pdf CY - Valencia ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - Sharma, Sparsh A1 - Schmidt, Heiko A1 - Klein, Marten T1 - Toward the use of a reduced-order and stochastic turbulence model for assessment of far-field sound radiation: Low Mach number jet flows T2 - Proceedings in Applied Mathematics and Mechanics Y1 - 2023 U6 - https://doi.org/10.1002/pamm.202300186 SN - 1617-7061 VL - 23 IS - 3 ER - TY - GEN A1 - Klein, Marten A1 - Kessler, Robert William A1 - Schmidt, Heiko T1 - On the influence of a wavy leading edge on the aerodynamic drag of a wing: A numerical parameter study T2 - STAB Jahresbericht 2023 KW - airfoil aerodynamics KW - passive flow control KW - CFD (RANS, LES) KW - wavy leading edge Y1 - 2023 UR - https://www.dlr.de/as/Portaldata/5/Resources/dokumente/veranstaltungen/stab_workshop/Jahresbericht2023.pdf UR - https://www.dlr.de/as/desktopdefault.aspx/tabid-128/268_read-1678/ VL - 21/2023 SP - 110 EP - 111 PB - Deutsche Strömungsmechanische Arbeitsgemeinschaft (STAB) CY - Göttingen, Germany ER -