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Related papers: Ambipolar Diffusion Heating in Turbulent Systems

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We present numerical simulations of reduced magnetohydrodynamic (RMHD) turbulence in a magnetic flux tube at the center of a polar coronal hole. The model for the background atmosphere is a solution of the momentum equation, and includes…

Solar and Stellar Astrophysics · Physics 2016-04-27 A. A. van Ballegooijen , M. Asgari-Targhi

2d hydrodynamical simulations are performed to examine the evaporation and condensation processes of giant molecular clouds in the hot phase of the interstellar medium. The evolution of cold and dense clouds is calculated in the subsonic…

Astrophysics · Physics 2009-10-31 Wolfgang Vieser , Gerhard Hensler

The fragmentation of gas to form stars in molecular clouds is intrinsically linked to the turbulence within them. These internal motions are set at the birth of the cloud and may vary with galactic environment and as the cloud evolves. In…

Astrophysics of Galaxies · Physics 2024-07-29 Jiten Dhandha , Zoe Faes , Rowan J. Smith

We studied experimentally the effect of turbulent thermal diffusion in a multi-fan turbulence generator which produces a nearly homogeneous and isotropic flow with a small mean velocity. Using Particle Image Velocimetry and Image Processing…

Fluid Dynamics · Physics 2009-11-11 A. Eidelman , T. Elperin , N. Kleeorin , I. Rogachevskii , I. Sapir-Katiraie

Advection is believed to be the dominant cooling mechanism in optically thin advection-dominated accretion flows (ADAF's). When outflow is considered, however, the first impression is that advection should be of opposite sign in the inflow…

High Energy Astrophysical Phenomena · Physics 2023-01-24 Cheng-Liang Jiao

The breakdown of flux-freezing in molecular clouds and protostellar discs is usually approximated by ambipolar diffusion at low densities or by resistive diffusion at high densities. Here I discuss an intermediate regime in which the Hall…

Astrophysics · Physics 2009-11-10 Mark Wardle

In the present work, we test the predictions of the AWSoM model, a global extended-MHD model capable of calculating the propagation and turbulent dissipation of Alfv\'en waves in any magnetic topology, against high resolution spectra of the…

Solar and Stellar Astrophysics · Physics 2014-01-06 R. Oran , E. Landi , B. van der Holst , I. V. Sokolov , T. I. Gombosi

This study explores heat and turbulent modulation in three-dimensional multiphase Rayleigh-B\'enard convection using direct numerical simulations. Two immiscible fluids with identical reference density undergo systematic variations in…

Fluid Dynamics · Physics 2024-08-26 Abbas Moradi Bilondi , Nicolò Scapin , Luca Brandt , Parisa Mirbod

Observations indicate that dense molecular filamentary clouds are sites of star formation. The filament width determines the most unstable scale for self-gravitational fragmentation and influences the stellar mass. Therefore, constraining…

Astrophysics of Galaxies · Physics 2025-05-09 Daisei Abe , Tsuyoshi Inoue , Shu-ichiro Inutsuka , Doris Arzoumanian

We discuss a new phenomenon of turbulent thermal diffusion associated with turbulent transport of aerosols in the atmosphere and in laboratory experiments. The essence of this phenomenon is the appearance of a nondiffusive mean flux of…

Astrophysics · Physics 2020-01-29 A. Eidelman , T. Elperin , N. Kleeorin , A. Krein , I. Rogachevskii , J. Buchholz , G. Gruenefeld

Nuclear burning plays a key role in a wide range of astrophysical stellar transients, including thermonuclear, pair instability, and core collapse supernovae, as well as kilonovae and collapsars. Turbulence is now understood to also play a…

Solar and Stellar Astrophysics · Physics 2020-02-07 Yossef Zenati , Robert T. Fisher

The large temperature difference between cold gas clouds around galaxies and the hot halos that they are moving through suggests that thermal conduction could play an important role in the circumgalactic medium. However, thermal conduction…

Astrophysics of Galaxies · Physics 2021-01-29 Richard Kooij , Asger Grønnow , Filippo Fraternali

We study experimentally turbulent thermal diffusion of small particles in inhomogeneous and anisotropic stably stratified turbulence produced by one oscillating grid in the air flow. The velocity fields have been measured using a Particle…

Fluid Dynamics · Physics 2022-09-20 E. Elmakies , O. Shildkrot , N. Kleeorin , A. Levy , I. Rogachevskii , A. Eidelman

Properties of candidate stars, forming out of molecular clouds, depend on the ambient conditions of the parent cloud. We present a series of 2D and 3D simulations of fragmentation of molecular clouds in starburst regions as well as clouds…

Solar and Stellar Astrophysics · Physics 2014-11-20 S. Hocuk , M. Spaans

It has been previously shown (Phys. Rev. E 66, 066305, 2002) that a non-rotating turbulent convection with nonuniform large-scale flows contributes to the turbulent heat flux. As a result, the turbulent heat flux depends explicitly not only…

Fluid Dynamics · Physics 2024-04-19 G. Orian , A. Asulin , E. Tkachenko , N. Kleeorin , A. Levy , I. Rogachevskii

The lower solar atmosphere consists of partially ionized turbulent plasmas harbouring velocity field, magnetic field and current density fluctuations. The correlations amongst these small scale fluctuations give rise to large scale flows…

Solar and Stellar Astrophysics · Physics 2009-04-23 V. Krishan , S. Masuda

A joint experimental and numerical investigation of turbulent flame front anchoring at externally heated walls is presented. The phenomenon is examined for lean hydrogen/air mixtures in a novel burner design, which comprises a cylindrical…

Fluid Dynamics · Physics 2020-03-25 S. Klukas , M. Sieber , M. Giglmaier , S. Schimek , C. O. Paschereit , N. A. Adams

The distribution of liquid water in ice-free clouds determines their radiative properties, a significant source of uncertainty in weather and climate models. Evaporation and turbulent mixing cause a cloud to display large variations in…

Fluid Dynamics · Physics 2021-06-02 J. Fries , G. Sardina , G. Svensson , B. Mehlig

The diffuse interstellar medium is dynamic, and its chemistry and evolution is determined by shock fronts as well as photodissociation. Shocks are implied by the supersonic motions and velocity dispersion often statistically called…

Astrophysics of Galaxies · Physics 2021-03-17 William T. Reach , Carl Heiles

Turbulent Radiative Mixing Layers (TRMLs) form at the interface of cold, dense gas and hot, diffuse gas in motion with each other. TRMLs are ubiquitous in and around galaxies on a variety of scales, including galactic winds and the…

Astrophysics of Galaxies · Physics 2023-07-03 Zirui Chen , Drummond B. Fielding , Greg L. Bryan