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Wall-pressure fluctuations are a practically robust input for real-time control systems aimed at modifying wall-bounded turbulence. The scaling behaviour of the wall-pressure--velocity coupling requires investigation to properly design a…

Fluid Dynamics · Physics 2024-01-11 Woutijn J. Baars , Giulio Dacome , Myoungkyu Lee

To fully evaluate a turbulent flow, Direct Numerical Simulation (DNS) is the most accurate method by far and requires considerable computational power and time; not optimum for industry standards. Developing an alternative model, providing…

Fluid Dynamics · Physics 2022-07-04 Indrajit Nandi , Saikat Saha , Sabir Subedi , Sumon Saha

Turbulent flows under transcritical conditions are present in regenerative cooling systems of rocker engines and extraction processes in chemical engineering. The turbulent flows and the corresponding heat transfer phenomena in these…

Fluid Dynamics · Physics 2017-12-08 Peter C. Ma , Xiang I. A. Yang , Matthias Ihme

We propose a supervised-machine-learning-based wall model for coarse-grid wall-resolved large-eddy simulation (LES). Our consideration is made on LES of turbulent channel flows with a first grid point set relatively far from the wall…

Fluid Dynamics · Physics 2021-06-18 Naoki Moriya , Kai Fukami , Yusuke Nabae , Masaki Morimoto , Taichi Nakamura , Koji Fukagata

This article presents a modelling of the formation of spanwise vorticity in the turbulent streaks of the oblique bands and spots of transitional plane Couette flow. A functional model is designed to mimic the coherent flow in the streaks.…

Fluid Dynamics · Physics 2015-12-10 Joran Rolland

Obtaining system parameters and reconstructing the full flow state from limited velocity observations using conventional fluid dynamics solvers can be prohibitively expensive. Here we employ machine learning algorithms to overcome the…

Fluid Dynamics · Physics 2024-10-17 Vladimir Parfenyev , Mark Blumenau , Ilia Nikitin

We design a nonlinear estimator for channel flows at $Re_{\tau}=180$ and $590$. The nonlinear estimator uses a linear estimator structure based on the linearised Navier-Stokes equations and explicitly calculates the nonlinear forcing from…

Fluid Dynamics · Physics 2024-08-26 Jitong Ding , Simon J. Illingworth

A promising and cost-effective method for numerical simulation of high Re wall-bounded flows is wall-modeled large-eddy simulation. Most wall models are formulated from the Reynolds-averaged Navier-Stokes equations (RANS). These RANS-based…

Fluid Dynamics · Physics 2021-01-08 Ahmed Elnahhas , Adrián Lozano-Durán , Parviz Moin

Particle Image Velocimetry (PIV) systems are often limited in their ability to fully resolve the spatiotemporal fluctuations inherent in turbulent flows due to hardware constraints. In this study, we develop models based on Rapid Distortion…

Fluid Dynamics · Physics 2021-01-15 C. Vamsi Krishna , Mengying Wang , Maziar S. Hemati , Mitul Luhar

Steady forcing at the wall of a channel flow is studied via DNS to assess its ability of yielding reductions of turbulent friction drag. The wall forcing consists of a stationary distribution of spanwise velocity that alternates in the…

Fluid Dynamics · Physics 2015-05-14 Claudio Viotti , Maurizio Quadrio , Paolo Luchini

A model based on a convolutional neural network (CNN) is designed to reconstruct the three-dimensional turbulent flows beneath a free surface using surface measurements, including the surface elevation and surface velocity. Trained on…

Fluid Dynamics · Physics 2023-04-12 Anqing Xuan , Lian Shen

In the current study, model expressions for fifth-order velocity moments obtained from the truncated Gram-Charlier series expansions model for a turbulent flow field probability density function are validated using data from direct…

Fluid Dynamics · Physics 2021-02-24 S. V. Poroseva , S. M. Murman

In this study, we explore the application of an artificial recurrent neural network (RNN) called Long Short-Term Memory (LSTM) as an alternative to a turbulent Reynolds-Averaged Navier-Stokes (RANS) model. The LSTM models are utilized to…

Fluid Dynamics · Physics 2023-07-27 Hugo D. Pasinato , Nicólas F. Moguilner Reh

A new slow growth formulation for DNS of wall-bounded turbulent flow is developed and demonstrated to enable extension of slow growth modeling concepts to complex boundary layer flows. As in previous slow growth approaches, the formulation…

Fluid Dynamics · Physics 2017-08-16 Victor Topalian , Todd A. Oliver , Rhys Ulerich , Robert D. Moser

We seek possible statistical consequences of the way a forcing term is added to the Navier--Stokes equations in the Direct Numerical Simulation (DNS) of incompressible channel flow. Simulations driven by constant flow rate, constant…

Fluid Dynamics · Physics 2016-01-20 Maurizio Quadrio , Bettina Frohnapfel , Yosuke Hasegawa

In this paper, the prediction capabilities of recurrent neural networks are assessed in the low-order model of near-wall turbulence by Moehlis {\it et al.} (New J. Phys. {\bf 6}, 56, 2004). Our results show that it is possible to obtain…

Analyzing large-scale data from simulations of turbulent flows is memory intensive, requiring significant resources. This major challenge highlights the need for data compression techniques. In this study, we apply a physics-informed Deep…

Fluid Dynamics · Physics 2022-04-20 Mohammadreza Momenifar , Enmao Diao , Vahid Tarokh , Andrew D. Bragg

The variance and spectra of wall-normal velocities are investigated for direct numerical simulations of turbulent flow in a channel, pipe, and zero-pressure-gradient boundary layer across a decade of friction Reynolds numbers. Spectra along…

Fluid Dynamics · Physics 2026-04-22 Michael Heisel , Rahul Deshpande , Gabriel G. Katul

We investigate the fluctuations of thermodynamic state-variables in compressible aerodynamic wall-turbulence, using results of direct numerical simulation (DNS) of compressible turbulent plane channel flow. The basic transport equations…

Fluid Dynamics · Physics 2016-07-01 G. A. Gerolymos , I. Vallet

Data assimilation (DA) plays a crucial role in extracting valuable information from flow measurements in fluid dynamics problems. Often only time-averaged data is available, which poses challenges for DA in the context of unsteady flow…

Fluid Dynamics · Physics 2024-05-30 Justin Plogmann , Oliver Brenner , Patrick Jenny