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Developing data-driven subgrid-scale (SGS) models for large eddy simulations (LES) has received substantial attention recently. Despite some success, particularly in a priori (offline) tests, challenges have been identified that include…

Fluid Dynamics · Physics 2021-02-05 Adam Subel , Ashesh Chattopadhyay , Yifei Guan , Pedram Hassanzadeh

The dynamic model for large-eddy simulation (LES) of turbulent flows requires test filtering the resolved velocity fields in order to determine model coefficients. However, test filtering is costly to perform in large-eddy simulation of…

Fluid Dynamics · Physics 2009-11-07 Stuart Chester , Fabrice Charlette , Charles Meneveau

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…

The effects of passive scalar anisotropy on subgrid-scale (SGS) physics and modeling for Large-Eddy Simulations are studied experimentally. Measurements are performed across a moderate Reynolds number wake flow generated by a heated…

Fluid Dynamics · Physics 2019-06-19 Hyung Suk Kang , Charles Meneveau

A major drawback of Boussinesq-type subgrid-scale stress models used in large-eddy simulations is the inherent assumption of alignment between large-scale strain rates and filtered subgrid-stresses. A priori analyses using direct numerical…

Fluid Dynamics · Physics 2023-05-09 Rahul Agrawal , Michael P. Whitmore , Kevin P. Griffin , Sanjeeb T. Bose , Parviz Moin

The effect of small scale forcing on large scale structures in $\beta$-plane two-dimensional (2D) turbulence is studied using long-term direct numerical simulations (DNS). We find that nonlinear effects remain strong at all times and for…

An adjoint-based variational optimal mixed model (VOMM) is proposed for subgrid-scale (SGS) closure in large-eddy simulation (LES) of turbulence. The stabilized adjoint LES equations are formulated by introducing a minimal regularization to…

Fluid Dynamics · Physics 2023-07-19 Zelong Yuan , Yunpeng Wang , Xiaoning Wang , Jianchun Wang

Progress toward understanding principles of nonlinear growth and saturation of large scale magnetic fields has emerged from comparison of theoretical models that incorporate the evolution of magnetic helicity with numerical simulations for…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Kiwan Park , E. G. Blackman

There is wide agreement that the accuracy of turbulence models suffer from their sensitivity with respect to physical input data, the uncertainties of user-elected parameters, as well as the model inadequacy. However, the application of…

Numerical Analysis · Mathematics 2015-08-07 Hoang A. Tran , Clayton G. Webster , Guannan Zhang

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

A new approach to turbulence simulation, based on a combination of large-eddy simulation (LES) for the whole flow and an array of non-space-filling quasi-direct numerical simulations (QDNS), which sample the response of near-wall turbulence…

Fluid Dynamics · Physics 2017-10-20 Neil D. Sandham , Roderick Johnstone , Christian T. Jacobs

This study proposes a rotationally invariant data-driven subgrid-scale (SGS) model for large-eddy simulation (LES) of wall-bounded turbulent flows. Building upon the multiscale convolutional neural network subgrid-scale model, which outputs…

Fluid Dynamics · Physics 2026-02-03 Bahrul Jalaali , Kie Okabayashi

In this paper we employ renormalized viscosity and thermal diffusivity to construct a subgrid-scale model for large eddy simulation (LES) of turbulent thermal convection. For LES, we add $\nu_\mathrm{ren} \propto \Pi_u^{1/3}…

Fluid Dynamics · Physics 2018-10-31 Sumit Vashishtha , Mahendra K. Verma

Ocean models at intermediate resolution (1/4 degree), which partially resolve mesoscale eddies, can be seen as Large eddy simulations (LES) of the primitive equations, in which the effect of unresolved eddies must be parameterized. In this…

Atmospheric and Oceanic Physics · Physics 2023-10-06 Pavel Perezhogin , Andrey Glazunov

A deep learning (DL) closure model for large-eddy simulation (LES) is developed and evaluated for incompressible flows around a rectangular cylinder at moderate Reynolds numbers. Near-wall flow simulation remains a central challenge in…

Fluid Dynamics · Physics 2023-07-19 Justin Sirignano , Jonathan F. MacArt

We present results of three-dimensional Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of turbulent gravity currents with a Discontinuous Galerkin (DG) Finite Elements method. In particular, we consider the…

Fluid Dynamics · Physics 2018-04-16 Caterina Bassi , Antonella Abbà , Luca Bonaventura , Lorenzo Valdettaro

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

Different approaches to using data-driven methods for subgrid-scale closure modeling have emerged recently. Most of these approaches are data-hungry, and lack interpretability and out-of-distribution generalizability. Here, we use {online}…

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

A new methodology based on energy flux similarity is suggested in this paper for large eddy simulation (LES) of transitional and turbulent flows. Existing knowledge reveals that the energy cascade generally exists in transitional and…

Fluid Dynamics · Physics 2019-10-31 Han Qi , Xinliang Li , Hao Zhou , Changping Yu
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