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Computational Fluid Dynamics (CFD) simulations using turbulence models are commonly used in engineering design. Of the different turbulence modeling approaches that are available, eddy viscosity based models are the most common for their…

Fluid Dynamics · Physics 2023-10-24 Minghan Chu , Weicheng Qian

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

We present a numerical methodology for construction of reduced order models, ROMs, of fluid flows through the combination of flow modal decomposition and regression analysis. Spectral proper orthogonal decomposition, SPOD, is applied to…

Fluid Dynamics · Physics 2019-07-24 Hugo F. S. Lui , William R. Wolf

Reynolds-averaged Navier--Stokes (RANS) closure must be sensitive to the flow physics, including nonlocality and anisotropy of the effective eddy viscosity. Recent approaches used forced direct numerical simulations to probe these effects,…

Fluid Dynamics · Physics 2024-09-24 Jessie Liu , Florian Schäfer , Spencer H. Bryngelson , Tamer A. Zaki , Ali Mani

In this paper, a stabilized proper orthogonal decomposition (POD) reduced-order model (ROM) is presented for the barotropic vorticity equation. We apply the POD-ROM model to mid-latitude simplified oceanic basins, which are standard…

Fluid Dynamics · Physics 2018-01-29 Omer San , Traian Iliescu

Standard eddy viscosity models, while robust, cannot represent backscatter and have severe difficulties with complex turbulence not at statistical equilibrium. This report gives a new derivation of eddy viscosity models from an equation for…

Numerical Analysis · Mathematics 2015-03-05 Nan Jiang , William Layton

We present a methodology to determine the best turbulence closure for an eddy-permitting ocean model through measurement of the error-landscape of the closure's subgrid spectral transfers and flux. We apply this method to 6 different…

Fluid Dynamics · Physics 2015-06-05 Jonathan Pietarila Graham , Todd Ringler

In burst-mode communication systems, the quality of frame synchronization (FS) at receivers significantly impacts the overall system performance. To guarantee FS, an extreme learning machine (ELM)-based synchronization method is proposed to…

Signal Processing · Electrical Eng. & Systems 2020-02-19 Chaojin Qing , Wang Yu , Bin Cai , Jiafan Wang , Chuan Huang

We introduce the Weak-form Estimation of Nonlinear Dynamics (WENDy) method for estimating model parameters for non-linear systems of ODEs. Without relying on any numerical differential equation solvers, WENDy computes accurate estimates and…

Machine Learning · Computer Science 2023-11-27 David M. Bortz , Daniel A. Messenger , Vanja Dukic

We put forth a long short-term memory (LSTM) nudging framework for the enhancement of reduced order models (ROMs) of fluid flows utilizing noisy measurements for air traffic improvements. Toward emerging applications of digital twins in…

Computational Physics · Physics 2021-03-08 Shady Ahmed , Suraj Pawar , Omer San , Adil Rasheed , Mandar Tabib

This article presents a Galerkin projection-based reduced-order modelling (ROM) approach for segregated fluid-structure interaction (FSI) problems, formulated within an Arbitrary Lagrangian Eulerian (ALE) framework at low Reynolds numbers…

Numerical Analysis · Mathematics 2025-07-24 Valentin Nkana Ngan , Giovanni Stabile , Andrea Mola , Gianluigi Rozza

This study proposes a novel method for developing discretization-consistent closure schemes for implicitly filtered Large Eddy Simulation (LES). Here, the induced filter kernel, and thus the closure terms, are determined by the properties…

Fluid Dynamics · Physics 2023-12-14 Andrea Beck , Marius Kurz

In this paper, we propose an equation-based parametric Reduced Order Model (ROM), whose accuracy is improved with data-driven terms added into the reduced equations. These additions have the aim of reintroducing contributions that in…

Numerical Analysis · Mathematics 2024-06-07 Anna Ivagnes , Giovanni Stabile , Gianluigi Rozza

A closure model is presented for large-eddy simulation (LES) based on the three-dimensional variational data assimilation algorithm. The approach aims at reconstructing high-fidelity kinetic energy spectra in coarse numerical simulations by…

Fluid Dynamics · Physics 2024-07-02 Sagy Ephrati , Arnout Franken , Erwin Luesink , Paolo Cifani , Bernard Geurts

We consider the question of fundamental limitations on the performance of eddy-viscosity closure models for turbulent flows, focusing on the Leith model for 2D {Large-Eddy Simulation}. Optimal eddy viscosities depending on the magnitude of…

Fluid Dynamics · Physics 2022-03-29 Pritpal Matharu , Bartosz Protas

The real-time fault monitoring and control of the Vacuum Assisted Resin Transfer Moulding (VARTM) production process requires a knowledge of the position of the epoxy flow-front inside the mould. Therefore, a fast and accurate flow-front…

Systems and Control · Computer Science 2019-02-27 Michael Nauheimer , Rishi Relan , Uffe Høgsbro Thygesen , Erik Lindström , Henrik Madsen

We report the first high-order eddy-resolving simulation of flow over a marine propeller using a recently developed high-order sliding-mesh method. This method employs the flux reconstruction framework and a new dynamic curved mortar…

Fluid Dynamics · Physics 2021-06-07 Bin Zhang , Chi Ding , Chunlei Liang

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}…

In the present study, we investigate different data-driven parameterizations for large eddy simulation of two-dimensional turbulence in the \emph{a priori} settings. These models utilize resolved flow field variables on the coarser grid to…

Computational Physics · Physics 2020-01-29 Suraj Pawar , Omer San , Adil Rasheed , Prakash Vedula

To realize efficient computational fluid dynamics (CFD) prediction of two-phase flow, a multi-scale framework was proposed in this paper by applying a physics-guided data-driven approach. Instrumental to this framework, Feature Similarity…

Computational Physics · Physics 2019-10-18 Han Bao , Jinyong Feng , Nam Dinh , Hongbin Zhang