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Related papers: Mixing in Supersonic Turbulence

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The probability density function (PDF) of the gas density in turbulent supersonic flows is investigated with high-resolution numerical simulations. In a systematic study, we compare the density statistics of compressible turbulence driven…

Astrophysics · Physics 2009-11-13 Christoph Federrath , Ralf S. Klessen , Wolfram Schmidt

The dimensional transition in turbulent jets of a shear-thinning fluid is studied via direct numerical simulations. Our findings reveal that under vertical confinement, the flow exhibits a unique mixed-dimensional (or 2.5D) state, where…

Fluid Dynamics · Physics 2024-08-20 Christian Amor , Giovanni Soligo , Andrea Mazzino , Marco Edoardo Rosti

The spatial organization of a passive scalar plume originating from a point source in a turbulent boundary layer is studied to understand its meandering characteristics. We focus shortly downstream of the isokinetic injection ($1.5\le…

Fluid Dynamics · Physics 2025-04-15 Isaiah E. Wall , Gokul Pathikonda

We performed a series of three-dimensional numerical simulations of supersonic homogeneous Euler turbulence with adaptive mesh refinement (AMR) and effective grid resolution up to 1024^3 zones. Our experiments describe non-magnetized driven…

Astrophysics · Physics 2016-08-30 Alexei G. Kritsuk , Michael L. Norman , Paolo Padoan

We present a Direct Numerical Simulation (DNS) study of buoyancy-driven bubbly flows in the presence of large scale driving that generates turbulence. On increasing the turbulence intensity: (a) the bubble trajectories become more curved,…

Fluid Dynamics · Physics 2023-06-22 Vikash Pandey , Dhrubaditya Mitra , Prasad Perlekar

The study of the exchange of momentum and energy between wave components of the turbulent velocity field, the so-called triad interactions, offers a unique way of visualizing and describing turbulence. Most often, this study has been…

Fluid Dynamics · Physics 2025-02-11 Preben Buchhave , Mengjia Ren , Clara Marika Velte

Direct numerical simulations of isotropically forced homogeneous stationary turbulence with an imposed passive scalar concentration gradient are compared with an analytical closure model which provides evolution equations for the mean…

Solar and Stellar Astrophysics · Physics 2015-06-03 J. E. Snellman , M. Rheinhardt , P. J. Käpylä , M. J. Mantere , A. Brandenburg

It is shown that magnetic islands generated by pressure-gradient-driven turbulence are common across a wide range of conditions. The interaction among turbulence, magnetic island and other large scale structures (the zonal flow and the…

Plasma Physics · Physics 2025-07-01 Daniele Villa , Nicolas Dubuit , Olivier Agullo , Xavier Garbet

We report results of a three dimensional, high resolution (up to 512^3) numerical investigation of supersonic compressible magnetohydrodynamic turbulence. We consider both forced and decaying turbulence. The model parameters are appropriate…

Astrophysics · Physics 2009-10-30 James M. Stone , Eve C. Ostriker , Charles F. Gammie

Galactic dynamo models take as input certain parameters of the interstellar turbulence, most essentially the correlation time $\tau$, root-mean-square turbulent speed $u$, and correlation scale $l$. However, these quantities are difficult,…

Astrophysics of Galaxies · Physics 2020-08-18 Luke Chamandy , Anvar Shukurov

Magnetic fields in several astrophysical objects are amplified and maintained by a dynamo mechanism, which is the conversion of the turbulent kinetic energy to magnetic energy. A dynamo that amplifies magnetic fields at scales $<$ the…

Astrophysics of Galaxies · Physics 2021-09-27 Amit Seta , Christoph Federrath

[abridged] We determine the relationship between turbulence energy and gas density variance for 15 molecular clouds in the Solar neighbourhood. We use the linewidths of the CO molecule as the probe of the turbulence energy (sonic Mach…

Astrophysics of Galaxies · Physics 2017-12-06 Jouni Kainulainen , Christoph Federrath

We report a non-perturbative study of the effects of shear flows on turbulence reduction in a decaying turbulence in two dimensions. By considering different initial power spectra and shear flows (zonal flows, combined zonal flows and…

Information Theory · Computer Science 2017-12-05 Eun-jin Kim , Ismail Movahedi

The interstellar medium (ISM) of our Galaxy is magnetized, compressible and turbulent, influencing many key ISM properties, like star formation, cosmic ray transport, and metal and phase mixing. Yet, basic statistics describing…

Astrophysics of Galaxies · Physics 2025-05-15 James R. Beattie , Christoph Federrath , Ralf S. Klessen , Salvatore Cielo , Amitava Bhattacharjee

We present a direct numerical and analytical study of driven supersonic MHD turbulence that is believed to govern the dynamics of star-forming molecular clouds. We describe statistical properties of the turbulence by measuring the velocity…

Astrophysics · Physics 2009-11-07 Stanislav Boldyrev , Aake Nordlund , Paolo Padoan

Turbulence plays a critical role in regulating star formation in molecular clouds and is also observed in simulations of primordial halos that host Population III (Pop III) stars. The relative velocity between baryons and dark matter at the…

We examine how well the physical properties of clumps in turbulent molecular clouds can be determined by measurements of observed clump structures. We compare simulated observations of three-dimensional numerical models of isothermal,…

Astrophysics · Physics 2009-11-07 Javier Ballesteros-Paredes , Mordecai-M. Mac Low

A roughly constant temperature over a wide range of densities is maintained in molecular clouds through radiative heating and cooling. An isothermal equation of state is therefore frequently employed in molecular cloud simulations. However,…

Astrophysics · Physics 2009-11-11 G. Pavlovski , M. D. Smith , M. -M. Mac Low

Turbulent characteristics within shear layer have been studied, recently, within vegetative canopy, buildings, dunes. Kevin-Helmholtz instability triggered hairpin vortex shedding has been widely concluded as the "signature" of mixing layer…

Fluid Dynamics · Physics 2020-03-16 Chao Wang , Ching Cheng

We investigate statistical properties of the passive scalar near boundaries (walls) in random (turbulent) flows assuming weakness of its diffusion. Then at advanced stages of the passive scalar mixing its unmixed residue is concentrated in…

Chaotic Dynamics · Physics 2015-03-13 A. Chernykh , V. Lebedev