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Related papers: Projected velocity statistics of interstellar turb…

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We investigate the velocity statistics by calculating the Biot--Savart velocity induced by vortex filaments in steady counterflow turbulence investigated in a previous study [Phys. Rev. B {\bf 81}, 104511 (2010)]. The probability density…

Other Condensed Matter · Physics 2015-05-20 Hiroyuki Adachi , Makoto Tsubota

We adapt the formalism of the statistical theory of 2D turbulence in the case where the Casimir constraints are replaced by the specification of a prior vorticity distribution. A new relaxation equation is obtained for the evolution of the…

Fluid Dynamics · Physics 2007-05-23 P. H. Chavanis

Small number statistics may heavily affect the structure of the broadening function in integrated spectra of galactic globular cluster centers. As a consequence, it is a priori unknown how closely line broadening measure- ments gauge the…

Astrophysics · Physics 2007-05-23 Simone R. Zaggia , Massimo Capaccioli , Giampaolo Piotto

We study, by means of adaptive mesh refinement hydro- and magnetohydrodynamical simulations that cover a wide range of scales (from kpc to sub-parsec), the dimension of the most dissipative structures and the injection scale of the…

Astrophysics · Physics 2009-11-13 Miguel A. de Avillez , Dieter Breitschwerdt

Supersonic turbulence in molecular clouds is a dominant agent that strongly affects the clouds' evolution and star formation activity. Turbulence may be initiated and maintained by a number of processes, acting at a wide range of physical…

Astrophysics of Galaxies · Physics 2014-11-20 C. M. Brunt , M. H. Heyer , M. -M. Mac Low

The velocity circulation, a measure of the rotation of a fluid within a closed path, is a fundamental observable in classical and quantum flows. It is indeed a Lagrangian invariant in inviscid classical fluids. In quantum flows, circulation…

Fluid Dynamics · Physics 2021-03-17 Nicolás P. Müller , Juan Ignacio Polanco , Giorgio Krstulovic

Convection and turbulence in stellar atmospheres have a significant effect on the emergent flux from late-type stars. The theoretical advancements in convection modelling over recent years have proved challenging for the observers to obtain…

Astrophysics · Physics 2015-06-24 Barry Smalley

The statistical properties of turbulence are considered to be universal at sufficiently small length scales, i. e., independent of boundary conditions and large-scale forces acting on the fluid. Analyzing data from numerical simulations of…

Astrophysics · Physics 2008-12-18 Wolfram Schmidt , Christoph Federrath , Ralf Klessen

To understand the earliest stages of planet formation, it is crucial to be able to predict the rate and the outcome of dust grains collisions, be it sticking and growth, bouncing, or fragmentation. The outcome of such collisions depends on…

Earth and Planetary Astrophysics · Physics 2015-06-05 Alexander Hubbard

The transitional regime of plane channel flow is investigated {above} the transitional point below which turbulence is not sustained, using direct numerical simulation in large domains. Statistics of laminar-turbulent spatio-temporal…

Fluid Dynamics · Physics 2020-09-16 Pavan V. Kashyap , Yohann Duguet , Olivier Dauchot

The velocity fluctuations for point vortex models are studied for the {\alpha}-turbulence equations, which are characterized by a fractional Laplacian relation between active scalar and the streamfunction. In particular, we focus on the…

Fluid Dynamics · Physics 2019-09-11 Giovanni Conti , Gualtiero Badin

A model is proposed for determining the distances to falling interstellar clouds in the galactic halo by measuring the cloud velocity and column density and assuming a model for the vertical density distribution of the Galactic interstellar…

Astrophysics · Physics 2009-10-28 Robert A. Benjamin , Laura Danly

Bose-Einstein condensates with their superfluidity property provide an interesting parallel to classical fluids. Due to the Kolmogorov spectrum of homogeneous turbulence the statistics of the incompressible velocity field is of great…

Quantum Gases · Physics 2022-08-16 Marcos A. G. dos Santos Filho , Francisco E. A. dos Santos

The understanding of turbulent flows is one of the biggest current challenges in physics, as no first-principles theory exists to explain their observed spatio-temporal intermittency. Turbulent flows may be regarded as an intricate…

Fluid Dynamics · Physics 2021-12-08 Juan Ignacio Polanco , Nicolás P. Müller , Giorgio Krstulovic

X-ray observations of the hot gas filling the intra-cluster medium provide a wealth of information on the dynamics of clusters of galaxies. The global equilibrium of the ICM is believed to be partially ensured by non-thermal pressure…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 E. Cucchetti , N. Clerc , E. Pointecouteau , P. Peille , F. Pajot

We investigate the statistics of turbulence in emulsions of two-immiscible fluids of same density. We compute for the first time velocity increments between points conditioned to be located in the same phase or in different phases and…

We review recent advances in the analytical and numerical modeling of the star formation rate in molecular clouds and discuss the available observational constraints. We focus on molecular clouds as the fundamental star formation sites,…

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

High-resolution numerical simulations are utilized to examine isotropic turbulence in a compressible fluid when long wavelength velocity fluctuations approach light speed. Spectral analysis reveals an inertial sub-range of relativistic…

High Energy Astrophysical Phenomena · Physics 2013-01-04 Jonathan Zrake , Andrew MacFadyen

The present work proposes a theory of isotropic and homogeneous turbulence for incompressible fluids, which assumes that the turbulence is due to the bifurcations associated to the velocity field. The theory is formulated using a…

Fluid Dynamics · Physics 2009-02-12 Nicola de Divitiis