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Related papers: Small-scale turbulent dynamo - a numerical investi…

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Using simulations of helically driven turbulence, it is shown that the ratio of kinetic to magnetic energy dissipation scales with the magnetic Prandtl number in power law fashion with an exponent of approximately 0.6. Over six orders of…

Solar and Stellar Astrophysics · Physics 2011-05-16 A. Brandenburg

In this paper, a physics-oriented stochastic kinetic scheme will be developed that includes random inputs from both flow and electromagnetic fields via a hybridization of stochastic Galerkin and collocation methods. Based on the BGK-type…

Computational Physics · Physics 2021-03-17 Tianbai Xiao , Martin Frank

Although the Shakura-Sunyaev $\alpha$ viscosity prescription has been highly successful in characterizing myriad astrophysical environments, it has proven to be partly inadequate in modelling turbulent stresses driven by the MRI. Hence, we…

Solar and Stellar Astrophysics · Physics 2016-05-03 M. Lingam , A. Bhattacharjee

It is a matter of experience that nonlinear waves in dispersive media, propagating primarily in one direction, may appear periodic in small space and time scales, but their characteristics --- amplitude, phase, wave number, etc. --- slowly…

Analysis of PDEs · Mathematics 2015-12-09 Jared C. Bronski , Vera Mikyoung Hur , Mathew A. Johnson

We derive the evolution equation of the average uncertainty energy for periodic/homogeneous incompressible Navier-Stokes turbulence and show that uncertainty is increased by strain rate compression and decreased by strain rate stretching.…

Fluid Dynamics · Physics 2025-07-11 Jin Ge , Joran Rolland , John-Christos Vassilicos

We demonstrate that a magneto-convection simulation incorporating essential physical processes governing solar surface convection exhibits turbulent small-scale dynamo action. By presenting a derivation of the energy balance equation and…

Solar and Stellar Astrophysics · Physics 2010-04-23 Jonathan Pietarila Graham , Robert Cameron , Manfred Schuessler

The small-scale turbulent dynamo is an important process contributing to the cosmic magnetization. In partially ionized astrophysical plasmas, the dynamo growth of magnetic energy strongly depends on the coupling state between ions and…

Astrophysics of Galaxies · Physics 2019-02-20 Siyao Xu , Sudip K. Garain , Dinshaw S. Balsara , A. Lazarian

We consider the problem of incompressible, forced, nonhelical, homogeneous and isotropic MHD turbulence with no mean magnetic field and large magnetic Prandtl number. This type of MHD turbulence is the end state of the turbulent dynamo,…

Small-scale effects of turbulent mixing are numerically investigated by applying the map-based, stochastic, one-dimensional turbulence (ODT) model to confined planar jets. The model validation is carried out for the momentum transport by…

Fluid Dynamics · Physics 2019-04-19 Marten Klein , Christian Zenker , Heiko Schmidt

We analyze the initial, kinematic stage of magnetic field evolution in an isotropic and homogeneous turbulent conducting fluid with a rough velocity field, v(l) ~ l^alpha, alpha<1. We propose that in the limit of small magnetic Prandtl…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev , Fausto Cattaneo

Performing accurate large eddy simulations in compressible, turbulent magnetohydrodynamics is more challenging than in non-magnetized fluids due to the complex interplay between kinetic, magnetic and internal energy at different scales.…

Fluid Dynamics · Physics 2019-10-23 Daniele Viganò , Ricard Aguilera-Miret , Carlos Palenzuela

Variational principle for Kolmogorov-Petrovsky-Piskunov (KPP) minimal front speeds provides an efficient tool for statistical speed analysis, as well as a fast and accurate method for speed computation. A variational principle based…

Analysis of PDEs · Mathematics 2009-11-10 James Nolen , Jack Xin

The physical nature of compressible turbulence is of fundamental importance in a variety of astrophysical settings. We present the first direct evidence that mean kinetic energy cascades conservatively beyond a transitional "conversion"…

Chaotic Dynamics · Physics 2015-05-30 Hussein Aluie , Shengtai Li , Hui Li

We present results of large-scale three-dimensional simulations of supersonic Euler turbulence with the piecewise parabolic method and multiple grid resolutions up to 2048^3 points. Our numerical experiments describe non-magnetized driven…

Astrophysics · Physics 2009-06-23 Alexei G. Kritsuk , Michael L. Norman , Paolo Padoan , Rick Wagner

Small-scale fluctuating magnetic fields of order $n$G are observed in supernova shocks and galaxy clusters, where its amplification is likely caused by the Biermann battery mechanism. However, these fields cannot be amplified further…

Astrophysics of Galaxies · Physics 2023-02-22 Justin Kin Jun Hew , Christoph Federrath

We study the dynamics of quantum skyrmions under a magnetic field gradient using neural network quantum states. First, we obtain a quantum skyrmion lattice ground state using variational Monte Carlo with a restricted Boltzmann machine as…

Disordered Systems and Neural Networks · Physics 2024-03-14 Ashish Joshi , Robert Peters , Thore Posske

We investigate the growth and structure of magnetic fields amplified by kinematic dynamo action in turbulence with non-zero kinetic helicity. We assume a simple Gaussian velocity correlation tensor, which allows us to consider very large…

Astrophysics · Physics 2009-11-13 Leonid Malyshkin , Stanislav Boldyrev

Most large-scale planetary magnetic fields are thought to be driven by low Rossby number convection of a low magnetic Prandtl number fluid. Here kinematic dynamo action is investigated with an asymptotic, rapidly rotating dynamo model for…

Geophysics · Physics 2016-12-14 Michael A. Calkins , Louie Long , David Nieves , Keith Julien , Steven M. Tobias

We use direct numerical simulations to study homogeneous, and isotropic turbulent flows of dilute polymer solutions at high Reynolds and Deborah numbers. We find that for small wavenumbers $k$, the kinetic energy spectrum shows…

Fluid Dynamics · Physics 2023-02-14 Marco E Rosti , Prasad Perlekar , Dhrubaditya Mitra

The purpose of this article is numerical verification of the theory of weak turbulence. We performed numerical simulation of an ensemble of nonlinearly interacting free gravity waves (swell) by two different methods: solution of primordial…

Fluid Dynamics · Physics 2011-01-04 A. O. Korotkevich , A. Pushkarev , D. Resio , V. E. Zakharov
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