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We present an analytical study of the statistical properties of integrated emission and velocity centroids for a slightly compressible turbulent slab model, to retrieve the underlying statistics of three-dimensional density and velocity…

Astrophysics · Physics 2009-11-10 F. Levrier

Shell models provide a simplified mathematical framework that captures essential features of incompressible fluid turbulence, such as the energy cascade and scaling of the fluid observables. We perform a precision analysis of the direct and…

Fluid Dynamics · Physics 2024-09-19 James Creswell , Viatcheslav Mukhanov , Yaron Oz

We present experimental observations of the velocity and spatial distribution of inertial particles dispersed in the turbulent downward flow through a vertical channel at $Re_{\tau} = 235$ and $335$. The working fluid is air laden with…

Fluid Dynamics · Physics 2019-04-16 Kee Onn Fong , Omid Amili , Filippo Coletti

A statistical analysis is presented of the turbulent velocity structure in the Orion Molecular Cloud at scales ranging from 70 AU to 30000 AU. Results are based on IR Fabry-Perot interferometric observations of shock and photon-excited H2…

Astrophysics · Physics 2016-08-30 M. Gustafsson , D. Field , J. L. Lemaire , F. P. Pijpers

In this presentation we review the link between the statistics of intensity fluctuations in spectral line data cubes with underlying statistical properties of turbulence in the interstellar medium. Both the formalism of Velocity Channel…

Astrophysics · Physics 2009-11-11 Dmitri Pogosyan , Alex Lazarian

Context. Tens of light hydrides and small molecules have now been detected over several hundreds sight lines sampling the diffuse interstellar medium (ISM) in both the Solar neighbourhood and the inner Galactic disk. They provide…

Astrophysics of Galaxies · Physics 2015-06-22 Benjamin Godard , Edith Falgarone , Guillaume Pineau Des Forêts

We propose a new, physically motivated fitting function for density PDFs in turbulent gas. Although it is known that when gas is isothermal, the PDF is approximately lognormal in the core, high-resolution simulations show large deviations…

Astrophysics of Galaxies · Physics 2013-07-02 Philip F. Hopkins

Turbulence influences the structure and dynamics of molecular clouds, and plays a key role in regulating star formation. We therefore need methods to accurately infer turbulence properties of molecular clouds from position-position-velocity…

Astrophysics of Galaxies · Physics 2025-09-12 Jayashree Narayan , Aris Tritsis , Christoph Federrath

Vortical structures of turbulence, i.e., vortex tubes and sheets, are studied using one-dimensional velocity data obtained in laboratory experiments for duct flows and boundary layers at microscale Reynolds numbers from 332 to 1934. We…

Fluid Dynamics · Physics 2009-11-13 H. Mouri , A. Hori , Y. Kawashima

In an experiment on a turbulent jet, we detect interfacial turbulent layers in a frame that moves, on average, along with the \tnti. This significantly prolongs the observation time of scalar and velocity structures and enables the…

Fluid Dynamics · Physics 2025-06-09 Ali R Khojasteh , Lyke K van Dalen , Coen Been , Jerry Westerweel , Willem van de Water

High resolution 21 cm observations of the Ursa Major cirrus revealed highly filamentary structures down to the 0.03 pc resolution. These filaments, still present in the line centroid map, show multi-Gaussian components and seem to be…

Astrophysics · Physics 2007-05-23 Marc-Antoine Miville-Deschenes , Gilles Joncas , Edith Falgarone

A theory of the probability distribution function (PDF) tails of the blob density in plasma edge turbulence is provided. A simplified model of the fast convective radial transport is used. The theoretically predicted PDF tails corroborate…

Plasma Physics · Physics 2009-11-13 Johan Anderson , Eun-jin Kim

[Abridged] The interstellar medium is observed to be organised in filamentary structures, as well as neutral (HI) and ionized (HII) bubbles. The expanding nature of these bubbles makes them shape their surroundings and possibly play a role…

We present simulations of coherent structures in compressible flows near the transition to turbulence using the Dissipative Particle Dynamics (DPD) method. The structures we find are remarkably consistent with experimental observations and…

We investigate the statistical properties, based on numerical simulations and analytical calculations, of a recently proposed stochastic model for the velocity field of an incompressible, homogeneous, isotropic and fully developed turbulent…

Fluid Dynamics · Physics 2016-04-28 Rodrigo M. Pereira , Christophe Garban , Laurent Chevillard

The small-scale statistical properties of velocity circulation in classical homogeneous and isotropic turbulent flows are assessed through a modeling framework that brings together the multiplicative cascade and the structural descriptions…

Fluid Dynamics · Physics 2022-08-17 Luca Moriconi , Rodrigo M. Pereira , Victor J. Valadão

We present a systematic analysis of the velocity structure functions (VSFs) of 167 molecular clouds with angular sizes greater than $\sim$176 arcmin$^2$ in three sectors of the Galactic mid-plane. We calculated the 1st- to 3rd-order VSFs…

We performed high resolution numerical simulations of homogenous and isotropic compressible turbulence, with an average 3D Mach number close to 0.3. We study the statistical properties of intermittency for velocity, density and entropy. For…

Chaotic Dynamics · Physics 2009-11-13 Roberto Benzi , Luca Biferale , Robert Fisher , Leo Kadanoff , Donald Lamb , Federico Toschi

We report numerical investigations of wave turbulence in a vibrating plate. The possibility to implement advanced measurement techniques and long time numerical simulations makes this system extremely valuable for wave turbulence studies.…

Soft Condensed Matter · Physics 2017-10-25 Nicolas Mordant , Benjamin Miquel

We performed numerical simulations of supersonic isothermal turbulence driven by mostly compressive large-scale forcing, using both a static grid and adaptive mesh refinement with an effective resolution N=768^3. After a transient phase…