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The development of a wall model using machine learning methods for the large-eddy simulation (LES) of separated flows is still an unsolved problem. Our approach is to leverage the significance of separated flow data, for which existing…

Fluid Dynamics · Physics 2024-12-25 Zhideng Zhou , Xin-lei Zhang , Guo-wei He , Xiaolei Yang

We present a proof-of-principle implementation of the first fully covariant filtering scheme applied to relativistic fluid turbulence. The filtering is performed with respect to special observers, identified dynamically as moving with the…

High Energy Astrophysical Phenomena · Physics 2025-01-07 T. Celora , M. J. Hatton , I. Hawke , N. Andersson

The explicit filtering method for large eddy simulation (LES,) which comprises integration of the governing equations without any added terms for sub-grid-scale modeling, and the application of a low-pass filter to transported fields, is…

Fluid Dynamics · Physics 2017-10-06 Joseph Mathew

Engineering simulations are usually based on complex, grid-based, or mesh-free methods for solving partial differential equations. The results of these methods cover large fields of physical quantities at very many discrete spatial…

Fluid Dynamics · Physics 2025-08-08 Eduardo Di Costanzo , Niklas Kühl , Jean-Christophe Marongiu , Thomas Rung

This article provides a reduced-order modelling framework for turbulent compressible flows discretized by the use of finite volume approaches. The basic idea behind this work is the construction of a reduced-order model capable of providing…

Fluid Dynamics · Physics 2024-05-31 Matteo Zancanaro , Valentin Nkana Ngan , Giovanni Stabile , Gianluigi Rozza

Systems comprising a turbulent channel flow overlaying a permeable bed can be found in a variety of industrial and natural applications (e.g. urban planning, fracking, submerged vegetation). One important realization of this system is at…

Fluid Dynamics · Physics 2017-08-01 Benjamin H. Sonin

This paper contains the latest installment of the authors' project on developing ensemble based data assimilation methodology for high dimensional fluid dynamics models. The algorithm presented here is a particle filter that combines model…

Numerical Analysis · Mathematics 2020-04-22 Colin Cotter , Dan Crisan , Darryl Holm , Wei Pan , Igor Shevchenko

This paper puts forth two new closure models for the proper orthogonal decomposition reduced-order modeling of structurally dominated turbulent flows: the dynamic subgrid-scale model and the variational multiscale model. These models, which…

Computational Physics · Physics 2015-05-28 Zhu Wang , Imran Akhtar , Jeff Borggaard , Traian Iliescu

This paper demonstrates the efficacy of data-driven localization mappings for assimilating satellite-like observations in a dynamical system of intermediate complexity. In particular, a sparse network of synthetic brightness temperature…

Atmospheric and Oceanic Physics · Physics 2018-03-06 Michèle De La Chevrotière , John Harlim

Obtaining predictive low-order models is a central challenge in fluid dynamics. Data-driven frameworks have been widely used to obtain low-order models of aerodynamic systems; yet, resulting models tend to yield predictions that grow…

The Reynolds-averaged Navier-Stokes (RANS) equations provide a computationally efficient method for solving fluid flow problems in engineering applications. However, the use of closure models to represent turbulence effects can reduce their…

Fluid Dynamics · Physics 2024-05-02 Oliver Brenner , Justin Plogmann , Pasha Piroozmand , Patrick Jenny

Modeling of turbulent flows is still challenging. One way to deal with the large scale separation due to turbulence is to simulate only the large scales and model the unresolved contributions as done in large-eddy simulation (LES). This…

Computational Physics · Physics 2019-10-03 Mathis Bode , Michael Gauding , Konstantin Kleinheinz , Heinz Pitsch

Hybrid Reynolds-averaged Navier Stokes large eddy simulation (RANS LES) methods have become popular for simulation of massively separated flows at high Reynolds numbers due to their reduced computational cost and good accuracy. The current…

Fluid Dynamics · Physics 2021-02-19 Gaurav Kumar , Ashoke De , Harish Gopalan

In this paper, we present ScalarFlow, a first large-scale data set of reconstructions of real-world smoke plumes. We additionally propose a framework for accurate physics-based reconstructions from a small number of video streams. Central…

Graphics · Computer Science 2020-11-23 Marie-Lena Eckert , Kiwon Um , Nils Thuerey

We investigate the combined use of a Kinect depth sensor and of a stochastic data assimilation method to recover free-surface flows. More specifically, we use a Weighted ensemble Kalman filter method to reconstruct the complete state of…

Fluid Dynamics · Physics 2016-01-05 Benoit Combès , Dominique Heitz , Anthony Guibert , Etienne Mémin

Data-driven dimensionality reduction methods such as proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) have proven to be useful for exploring complex phenomena within fluid dynamics and beyond. A well-known…

Fluid Dynamics · Physics 2022-12-27 Elena Marensi , Gökhan Yalnız , Björn Hof , Nazmi Burak Budanur

The predictive accuracy of wall-modelled LES is influenced by a combination of the subgrid model, the wall model, the numerical dissipation induced primarily by the convective numerical scheme, and also by the density and topology of the…

Fluid Dynamics · Physics 2020-09-02 Timofey Mukha , Rickard E. Bensow , Mattias Liefvendahl

In this review, the methodology of large eddy simulations (LES) is introduced and applications in astrophysics are discussed. As theoretical framework, the scale decomposition of the dynamical equations for neutral fluids by means of…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-10 Wolfram Schmidt

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

Traditional data assimilation uses information obtained from the propagation of one physics-driven model and combines it with information derived from real-world observations in order to obtain a better estimate of the truth of some natural…

Computational Engineering, Finance, and Science · Computer Science 2022-10-24 Andrey A Popov , Adrian Sandu