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Transition to turbulence is due to the instability of a laminar flow subject to a disturbance. This complicated problem can be explained using a new proposed energy gradient theory in our previous study. This theory is extended to the…

Chaotic Dynamics · Physics 2007-05-23 Hua-Shu Dou

In the scientific literature, the term emergent phenomena is invoked in the context of a collective behavior observed in a complex adaptive system that exhibits no correspondence with the behavior of the system constituents. Although this…

Physics and Society · Physics 2021-06-29 Nitish Kumar Gupta , A. M. Jayannavar

In this paper we develop new techniques for revealing geometrical structures in phase space that are valid for aperiodically time dependent dynamical systems, which we refer to as Lagrangian descriptors. These quantities are based on the…

Chaotic Dynamics · Physics 2013-08-05 Ana M. Mancho , Stephen Wiggins , Jezabel Curbelo , Carolina Mendoza

A new phenomenological model of turbulent fluctuations is constructed by considering the Lagrangian dynamics of 4 points (the tetrad). The closure of the equations of motion is achieved by postulating an anisotropic, i.e. tetrad shape…

chao-dyn · Physics 2009-10-31 Michael Chertkov , Alain Pumir , Boris I. Shraiman

The Lagrangian probability-density-function model, proposed in Part I for dense particle-laden turbulent flows, is validated here against Eulerian-Lagrangian direct numerical simulation (EL) data for different homogeneous flows, namely…

Fluid Dynamics · Physics 2018-03-02 Alessio Innocenti , Rodney O Fox , Maria Vittoria Salvetti , Sergio Chibbaro

We explore the relationship between mechanical systems describing the motion of a particle with the mechanical systems describing a continuous medium. More specifically, we will study how the so-called intermediate integrals or fields of…

Mathematical Physics · Physics 2020-07-15 Ricardo J. Alonso-Blanco

We consider a class of Lorentz gauge gravity theories within Riemann-Cartan geometry which admits a topological phase in the gravitational sector. The dynamic content of such theories is determined only by the contortion part of the Lorentz…

General Relativity and Quantum Cosmology · Physics 2012-04-12 D. G. Pak , Youngman Kim , Takuya Tsukioka

Some recently proposed approximations to follow the non--linear evolution of collisionless matter perturbations in the universe are reviewed. The first one, called frozen--flow approximation, is an Eulerian method within Newtonian theory,…

Astrophysics · Physics 2007-05-23 S. Matarrese , P. Catelan , F. Lucchin , L. Moscardini , O. Pantano , D. Saez

The statistical properties of velocity and acceleration fields along the trajectories of fluid particles transported by a fully developed turbulent flow are investigated by means of high resolution direct numerical simulations. We present…

Chaotic Dynamics · Physics 2007-05-23 L. Biferale , G. Boffetta , A. Celani , B. J. Devenish , A. Lanotte , F. Toschi

We are interested in studying an unsteady fluid-structure interaction problem in a three-dimensional space. We consider a homogeneous Newtonian fluid which is modeled by the Navier-Stokes equations. Whereas the motion of the structure is…

Analysis of PDEs · Mathematics 2019-10-14 Fatima Abbas , Ayman Mourad

The evolution of density perturbations is analysed in a modified theory of gravity with a nonminimal coupling between curvature and matter. We consider the broken degeneracy between the choices of matter Lagrangian for a perfect fluid,…

General Relativity and Quantum Cosmology · Physics 2026-01-26 Miguel Barroso Varela , Orfeu Bertolami

This paper surveys results found by the authors in the previous papers (see for example, A. Duyunova, V. Lychagin, S. Tychkov, Differential invariants for spherical layer flows of a viscid fluid, Journal of Geometry and Physics, 130,…

Mathematical Physics · Physics 2020-04-06 Anna Duyunova , Valentin Lychagin , Sergey Tychkov

We analyze the statistics of turbulent velocity fluctuations in the time domain. Three cases are computed numerically and compared: (i) the time traces of Lagrangian fluid particles in a (3D) turbulent flow (referred to as the "dynamic"…

Statistical Mechanics · Physics 2007-05-23 L. Chevillard , S. G. Roux , E. Leveque , N. Mordant , J. -F. Pinton , A. Arneodo

The purpose of this paper is to examine the Lagrangian stochastic modeling of the fluid velocity seen by inertial particles in a nonhomogeneous turbulent flow. A new Langevin-type model, compatible with the transport equation of the drift…

Fluid Dynamics · Physics 2009-07-01 Boris Arcen , Anne Tanière

For a distribution advected by a simple chaotic map with diffusion, the "strange eigenmode" is investigated from the Lagrangian (material) viewpoint and compared to its Eulerian (spatial) counterpart. The eigenmode embodies the balance…

Chaotic Dynamics · Physics 2007-12-12 Jean-Luc Thiffeault

A dynamical system framework is used to describe transport processes in plasmas embedded in a magnetic field. For periodic systems with one degree of freedom the Poincar\'e map provides a splitting of the phase space into regions where…

Plasma Physics · Physics 2015-07-28 M. V. Falessi , F. Pegoraro , T. J. Schep

Particles are a widespread tool for obtaining information from fluid flows. When Eulerian data are unavailable, they may be employed to estimate flow fields or to identify coherent flow structures. Here we numerically examine the…

Fluid Dynamics · Physics 2023-06-22 O. Outrata , M. Pavelka , J. Hron , M. La Mantia , J. I. Polanco , G. Krstulovic

We develop a covariant variational framework for relativistic electromagnetic continua (fluids and solid) based on Hamilton's principle formulated directly in the material description. The approach extends the geometric theory of…

Mathematical Physics · Physics 2025-11-25 Francçois Gay-Balmaz

We investigate the Lagrangian properties of homogeneous, stratified turbulence at different Brunt-V\"ais\"al\"a frequencies.We show increasing vertical confinement of trajectories with increasing stratification strength highlighting the…

Fluid Dynamics · Physics 2025-03-31 Arun Kumar Varanasi

We explore the application of the reference map technique, originally developed for the Eulerian simulation of solid mechanics, in Lagrangian kinematics of fluid flows. Unlike traditional methods based on explicit particle tracking, the…

Fluid Dynamics · Physics 2024-12-04 Imran Hayat , Ryan T. Black , George Ilhwan Park