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We present numerical simulation of 2D turbulent flow using a new model for the subgrid scales which are computed using a dynamic equation linking the subgrid scales with the resolved velocity. This equation is not postulated, but derived…

Fluid Dynamics · Physics 2009-11-07 J. -P. Laval , B. Dubrulle , S. Nazarenko

New large eddy simulation (LES) turbulence models for incompressible magnetohydrodynamics (MHD) derived from the variational multiscale (VMS) formulation for finite element simulations are introduced. The new models include the variational…

Computational Physics · Physics 2015-05-20 David Sondak , John N. Shadid , Assad A. Oberai , Roger P. Pawlowski , Eric C. Cyr , Tom M. Smith

Large Eddy Simulations (LES) are becoming increasingly viable due to the growth in computational power the last few decades, and subgrid stress modelling plays a large role in the accuracy of LES. A new class of neural network models, S4…

Fluid Dynamics · Physics 2025-11-17 Andy Wu , Sanjiva K. Lele

Large-eddy simulation (LES) of a turbulent flow through an array of building-like obstacles is an idealized model to study transport of contaminants in the urban atmospheric boundary layer (UABL). A reasonably accurate LES prediction of…

Fluid Dynamics · Physics 2017-11-09 Jahrul M Alam , Luke P. J. Fitzpatrick

We propose a new model of turbulence for use in large-eddy simulations (LES). The turbulent force, represented here by the turbulent Lamb vector, is divided in two contributions. The contribution including only subfilter fields is…

Fluid Dynamics · Physics 2009-11-11 Jean-Philippe Laval , Berengere Dubrulle

Large eddy simulation (LES) of turbulence in complex geometries and domains is often conducted with high aspect ratio resolution cells of varying shapes and orientations. The effects of such anisotropic resolution are often simplified or…

Fluid Dynamics · Physics 2019-11-20 Sigfried Haering , Myoungkyu Lee , Robert D. Moser

We study the sub-grid scale characteristics of a vorticity-transport-based approach for large-eddy simulations. In particular, we consider a multi-dimensional upwind scheme for the vorticity transport equations and establish its properties…

Fluid Dynamics · Physics 2021-02-05 Daniel Foti , Karthik Duraisamy

We parameterize sub-grid scale (SGS) fluxes in sinusoidally forced two-dimensional turbulence on the $\beta$-plane at high Reynolds numbers (Re$\sim$25000) using simple 2-layer Convolutional Neural Networks (CNN) having only…

Fluid Dynamics · Physics 2023-04-12 Kaushik Srinivasan , Mickael D. Chekroun , James C. McWilliams

FEARLESS (Fluid mEchanics with Adaptively Refined Large Eddy SimulationS) is a new numerical scheme arising from the combined use of subgrid scale (SGS) model for turbulence at the unresolved length scales and adaptive mesh refinement (AMR)…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 L. Iapichino , A. Maier , W. Schmidt , J. C. Niemeyer

Predicting the large-scale dynamics of three-dimensional (3D) turbulence is challenging for machine learning approaches. This paper introduces a transformer-based neural operator (TNO) to achieve precise and efficient predictions in the…

Fluid Dynamics · Physics 2024-06-07 Zhijie Li , Tianyuan Liu , Wenhui Peng , Zelong Yuan , Jianchun Wang

In large-eddy simulations of atmospheric boundary layer turbulence, the lumped coefficient in the eddy-diffusion subgrid-scale (SGS) model is known to depend on scale for the case of inert scalars. This scale dependence is predominant near…

Atmospheric and Oceanic Physics · Physics 2016-08-16 Jean-François Vinuesa , Fernando Porté-Agel , Sukanta Basu , Rob Stoll

We present large-eddy-simulation (LES) modeling approaches for the simulation of atmospheric boundary layer turbulence that are of direct relevance to wind energy production. In this paper, we study a GABLS benchmark problem using…

Computational Engineering, Finance, and Science · Computer Science 2024-10-02 Ananias Tomboulides Matthew Churchfield , Paul Fischer , Michael Sprague , Misun Min

The effect of grid resolution on large eddy simulation (LES) of wall-bounded turbulent flow is investigated. A channel flow simulation campaign involving systematic variation of the streamwise ($\Delta x$) and spanwise ($\Delta z$) grid…

Fluid Dynamics · Physics 2018-05-23 Saleh Rezaeiravesh , Mattias Liefvendahl

Turbulent flow has been extensively studied using computational fluid dynamics (CFD) simulations since turbulent flow regime is so frequently encountered in both academic and engineering applications. The high-fidelity simulation of the…

Fluid Dynamics · Physics 2024-05-21 Minghan Chu

Turbulence in compressible plasma plays a key role in many areas of astrophysics and engineering. The extreme plasma parameters in these environments, e.g. high Reynolds numbers, supersonic and super-Alfvenic flows, however, make direct…

Large Eddy Simulation (LES) with dynamic Smagorinsky model has been applied to numerically investigate the complicated flow structures that evolve in the near wake of a cylindrical after body aligned with a uniform Mach 2.46 flow. Mean flow…

Fluid Dynamics · Physics 2021-02-16 Pratik Das , Ashoke De

The work of Ansumali \textit{et al.}\cite{Ansumali} is extended to Two Dimensional Magnetohydrodynamic (MHD) turbulence in which energy is cascaded to small spatial scales and thus requires subgrid modeling. Applying large eddy simulation…

Plasma Physics · Physics 2017-12-21 Christopher Flint , George Vahala

Reliably predictive simulation of complex flows requires a level of model sophistication and robustness exceeding the capabilities of current Reynolds-averaged Navier-Stokes (RANS) models. The necessary capability can often be provided by…

Fluid Dynamics · Physics 2022-01-20 Sigfried W. Haering , Todd A. Oliver , Robert D. Moser

One of the more promising recent approaches to turbulence modelling is the Variational Multiscale Large Eddy Simulation (VMS LES) method proposed by Hughes et al. [Comp. Visual. Sci., vol. 3, pp. 47-59, 2000]. This method avoids several…

Computational Physics · Physics 2007-05-23 Thor Gjesdal , Carl Erik Wasberg , Bjorn Anders Pettersson Reif , Oyvind Andreassen

Symmetry-based analyses of multiscale velocity gradients highlight that strain self-amplification (SS) and vortex stretching (VS) drive forward energy transfer in turbulent flows. By contrast, a strain-vorticity covariance mechanism…

Fluid Dynamics · Physics 2026-01-14 Rahul Arun , Mostafa Kamal , Tim Colonius , Perry L. Johnson