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Related papers: Star-Convex structures as prototypes of Lagrangian…

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The classical picture of a star-forming filament is a near-equilibrium structure, with collapse dependent on its gravitational criticality. Recent observations have complicated this picture, revealing filaments as a mess of apparently…

Astrophysics of Galaxies · Physics 2014-02-12 Nickolas Moeckel , Andreas Burkert

Boundary driven diffusive systems describe a broad range of transport phenomena. We study large deviations of the density profile in these systems, using numerical and analytical methods. We find that the large deviation may be…

Statistical Mechanics · Physics 2015-10-07 Guy Bunin , Yariv Kafri , Daniel Podolsky

In this paper we apply the method of Lagrangian descriptors to explore the geometrical structures in phase space that govern the dynamics of dissipative systems. We demonstrate through many classical examples taken from the nonlinear…

Dynamical Systems · Mathematics 2021-10-04 V. J. García-Garrido , J. García-Luengo

Our ability to predict the structure and evolution of stars is in part limited by complex, 3D hydrodynamic processes such as convective boundary mixing. Hydrodynamic simulations help us understand the dynamics of stellar convection and…

We investigate a theoretical framework for modeling fluid turbulence based on the formalism of exact coherent structures (ECSs). Although highly promising, existing evidence for the role of ECSs in turbulent flows is largely circumstantial…

Fluid Dynamics · Physics 2021-08-04 Michael C. Krygier , Joshua L. Pughe-Sanford , Roman O. Grigoriev

We analyse the flow organization of turbulent fountains in stratified media under different conditions, using three-dimensional finite-time Lyapunov exponents. The dominant Lagrangian coherent structures responsible for the transport…

We introduce Lagrangian Flow Networks (LFlows) for modeling fluid densities and velocities continuously in space and time. By construction, the proposed LFlows satisfy the continuity equation, a PDE describing mass conservation in its…

Machine Learning · Computer Science 2023-12-15 F. Arend Torres , Marcello Massimo Negri , Marco Inversi , Jonathan Aellen , Volker Roth

The transport by materially coherent eddies is studied in a two-layer quasigeostrophic model of geophysical turbulence. The coherent eddies are identified by closed contours of the Lagrangian-averaged vorticity deviation obtained from…

Atmospheric and Oceanic Physics · Physics 2019-12-25 Wenda Zhang , Christopher L. P. Wolfe , Ryan Abernathey

We provide a new existence result for weak solutions to the one-dimensional Euler equations with a maximal density constraint, corresponding to a unilateral constraint on the density. Such models arise in the description of congestion…

Analysis of PDEs · Mathematics 2026-04-06 Charlotte Perrin

Previous studies using numerical simulations have demonstrated that the shape of the cosmic web can be described by studying the Lagrangian displacement field. We extend these analyses, showing that it is now possible to perform a…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Florent Leclercq , Jens Jasche , Guilhem Lavaux , Benjamin Wandelt , Will Percival

We study uncertainty in the dynamics of time-dependent flows by identifying barriers and enhancers to stochastic transport. This topological segmentation is closely related to the theory of Lagrangian coherent structures and is based on a…

Geophysics · Physics 2020-09-11 Tobias Rapp , Carsten Dachsbacher

Finite-time coherent sets (FTCSs) are distinguished regions of phase space that resist mixing with the surrounding space for some finite period of time; physical manifestations include eddies and vortices in the ocean and atmosphere,…

Dynamical Systems · Mathematics 2023-10-10 Gary Froyland , Péter Koltai

We investigate statistics of large-scale structures from large-eddy simulation (LES) of turbulent channel flow at friction Reynolds numbers $Re_\tau = 2 {\rm k}$ and $200 {\rm k}$. To properly capture the behaviour of large-scale…

Fluid Dynamics · Physics 2015-05-18 D. Chung , B. J. McKeon

The aim of this paper is to prove that a three dimensional Lagrangian flow which defines equatorially trapped water waves is dynamically possible. This is achieved by applying a mixture of analytical and topological methods to prove that…

Analysis of PDEs · Mathematics 2015-05-08 Silvia Sastre-Gomez

The output from an eddy-resolved multi-layered circulation model is used to analyze the vertical structure of simulated deep-sea eddies in the Japan Basin of the Japan/East Sea constrained by bottom topography. We focus on Lagrangian…

Atmospheric and Oceanic Physics · Physics 2015-05-20 S. V. Prants , V. I. Ponomarev , M. V. Budyansky , M. Yu. Uleysky , P. A. Fyman

We introduce the concept of a "transitory" dynamical system---one whose time-dependence is confined to a compact interval---and show how to quantify transport between two-dimensional Lagrangian coherent structures for the Hamiltonian case.…

Chaotic Dynamics · Physics 2015-03-17 B. A. Mosovsky , J. D. Meiss

The statistical properties of fluid particles transported by a fully developed turbulent flow are investigated by means of high resolution direct numerical simulations. Single trajectory statistics is investigated in a time range spanning…

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

The stellar velocity fields of elliptical galaxies hold clues to their dynamical structure and origin. The construction of velocity field models is greatly simplified by assuming an approximate geometrical form for the streamlines of the…

Astrophysics · Physics 2009-10-30 R. F. Anderson , Thomas S. Statler

Simulating oil transport in the ocean can be done successfully provided that accurate ocean currents and surface winds are available -- this is often too big of a challenge. Deficient ocean currents can sometimes be remediated by…

Atmospheric and Oceanic Physics · Physics 2021-06-18 Rodrigo Duran , Tor Nordam , Mattia Serra , Chris Barker

This study presents several new observations from the study of a warm-core ring (WCR) in the Gulf of Mexico based on the ECCO2 global ocean simulation. Using Lagrangian coherent structures (LCS) techniques to investigate this flow reveals a…

Atmospheric and Oceanic Physics · Physics 2015-06-17 Doug Lipinski , Kamran Mohseni