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Dynamo action in a fully helical Beltrami (ABC) flow is studied using both direct numerical simulations and subgrid modeling. Sufficient scale separation is given in order to allow for large-scale magnetic energy build-up. Growth of…

Fluid Dynamics · Physics 2009-11-13 P. D. Mininni

Using direct simulations of hydromagnetic turbulence driven by random polarized waves it is shown that dynamo action is possible over a wide range of magnetic Prandtl numbers from 10^-3 to 1. Triply periodic boundary conditions are being…

Astrophysics · Physics 2010-01-15 Axel Brandenburg

This paper considers a possibility of magnetic-field generation by local turbulent flows at the bottom of convective zone. The cycle of magnetic-field generation in this model can be represented in the form of sequency of processes. There…

Solar and Stellar Astrophysics · Physics 2013-10-18 Andrey G. Tlatov

The small-scale dynamo is a process by which turbulent kinetic energy is converted into magnetic energy, and thus is expected to depend crucially on the nature of turbulence. In this work, we present a model for the small-scale dynamo that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jennifer Schober , Dominik Schleicher , Christoph Federrath , Ralf Klessen , Robi Banerjee

We investigate the instabilities and associated bifurcation structure near the onset of rotating magnetoconvection of low Prandtl number fluids by performing three dimensional direct numerical simulations. Previous studies considered zero…

Fluid Dynamics · Physics 2024-04-15 Snehashish Sarkar , Sutapa Mandal , Pinaki Pal

Context: Direct numerical simulations have shown that the dynamo is efficient even at low Prandtl numbers, i.e., the critical magnetic Reynolds number Rm_c necessary for the dynamo to be efficient becomes smaller than the hydrodynamic…

Plasma Physics · Physics 2011-11-11 Eric Buchlin

Context: During the last decades, significant progress has been made in both numerical simulations of turbulent dynamo and theoretical understanding of turbulence. However, there is still lack of quantitative comparison between the…

Fluid Dynamics · Physics 2026-04-08 A. V. Kopyev , A. S. Il'yn , V. A. Sirota , K. P. Zybin

A numerical study of dynamos in rotating convecting plane layers is presented which focuses on magnetic energies and dissipation rates, and the generation of mean fields (where the mean is taken over horizontal planes). The scaling of the…

Fluid Dynamics · Physics 2015-06-22 A. Tilgner

We study the instability of a B\'enard layer subject to a vertical uniform magnetic field, in which the fluid obeys the Maxwell-Cattaneo (MC) heat flux-temperature relation. We extend the work of Bissell (Proc. R. Soc. A, 472: 20160649,…

Fluid Dynamics · Physics 2020-10-15 I. A. Eltayeb , D. W. Hughes , M. R. E. Proctor

The onset of convection in the form of magneto-inertial waves in a rotating fluid sphere permeated by a constant axial electric current is studied through a perturbation analysis. Explicit expressions for the dependence of the Rayleigh…

Fluid Dynamics · Physics 2021-01-19 Radostin D. Simitev , Friedrich H. Busse

The magnetic field measured in the Madison Dynamo Experiment shows intermittent periods of growth when an axial magnetic field is applied. The geometry of the intermittent field is consistent with the fastest growing magnetic eigenmode…

Plasma Physics · Physics 2009-11-11 M. D. Nornberg , E. J. Spence , R. D. Kendrick , C. M. Jacobson , C. B. Forest

We use the machinery usually employed for studying the onset of Rayleigh--B\'enard convection in hydro- and magnetohydro-dynamic settings to address the onset of convection induced by the magnetothermal instability and the…

Fluid Dynamics · Physics 2016-06-01 Himanshu Gupta , Shailendra K. Rathor , Martin E. Pessah , Sagar Chakraborty

We study dynamo action using numerical simulations of planar Boussinesq convection at rapid rotation (low Ekman numbers, Ek), focusing on subcritical dynamo action in which the dynamo is sustained for Rayleigh numbers, Ra, below the…

Fluid Dynamics · Physics 2020-11-13 Robert G. Cooper , Paul J. Bushby , Celine Guervilly

We have tested the ability of driven turbulence to generate magnetic field structure from a weak uniform field using three dimensional numerical simulations of incompressible turbulence. We used a pseudo-spectral code with a numerical…

Astrophysics · Physics 2009-10-31 Jungyeon Cho , Ethan T. Vishniac

We present a three--pronged numerical approach to the dynamo problem at low magnetic Prandtl numbers $P_M$. The difficulty of resolving a large range of scales is circumvented by combining Direct Numerical Simulations, a Lagrangian-averaged…

Geophysics · Physics 2009-11-10 Y. Ponty , P. D. Mininni , D. C. Montgomery , J. -F. Pinton , H. Politano , A. Pouquet

The effect of a homogeneous magnetic field on surface-tension-driven B\'{e}nard convection is studied by means of direct numerical simulations. The flow is computed in a rectangular domain with periodic horizontal boundary conditions and…

Fluid Dynamics · Physics 2009-11-23 Thomas Boeck

Direct numerical simulations are carried out to study flow structure and transport properties in turbulent Rayleigh-B\'{e}nard convection in a cylindrical cell of aspect ratio one with an imposed axial magnetic field. Flows at the Prandtl…

Fluid Dynamics · Physics 2020-06-24 Ruslan Akhmedagaev , Oleg Zikanov , Dmitry Krasnov , Joerg Schumacher

We investigate the effect of external horizontal magnetic field applied on the convection rolls obliquely (at an angle $\phi$ with the $x$-axis) in electrically conducting low Prandtl number fluids under the paradigm of the…

Fluid Dynamics · Physics 2025-03-18 Snehashish Sarkar , Sutapa Mandal , Pinaki Pal

Kinematic dynamo in incompressible isotropic turbulent flows with high magnetic Prandtl number is considered. The approach interpreting an arbitrary magnetic field distribution as a superposition of localized perturbations (blobs) is…

Fluid Dynamics · Physics 2023-10-26 A. S. Il'yn , A. V. Kopyev , V. A. Sirota , K. P. Zybin

Several lines of evidence suggest that protogalactic and galactic environments manage to grow magnetic field very rapidly. This makes the theoretical problem of achieving rapid growth of magnetic fields in such environments difficult.…

Astrophysics · Physics 2009-11-10 D. S. Balsara , J. S. Kim , M. M. Mac Low , G. Mathews