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Related papers: Influence of turbulence on the dynamo threshold

200 papers

To elucidate the influence of shear flow on the generation of magnetic field (the dynamo effect), we study the kinematic limit where the magnetic field does not backreact on the velocity field. By non-perturbatively incorporating the effect…

Fluid Dynamics · Physics 2009-07-09 Nicolas Leprovost , Eun-Jin Kim

Turbulence in the protoplanetary disks induces collisions between dust grains, and thus facilitates grain growth. We investigate the two fundamental assumptions of the turbulence in obtaining grain collisional velocities -- the kinetic…

Solar and Stellar Astrophysics · Physics 2020-03-25 Munan Gong , Alexei V. Ivlev , Bo Zhao , Paola Caselli

A central problem of turbulence theory is to produce a predictive model for turbulent fluxes. These have profound implications for virtually all aspects of the turbulence dynamics. In magnetic confinement devices, drift-wave turbulence…

Plasma Physics · Physics 2020-07-01 R. A. Heinonen , P. H. Diamond

Several recent advances in turbulent dynamo theory are reviewed. High resolution simulations of small-scale and large-scale dynamo action in periodic domains are compared with each other and contrasted with similar results at low magnetic…

Solar and Stellar Astrophysics · Physics 2012-07-10 Axel Brandenburg , Dmitry Sokoloff , Kandaswamy Subramanian

We present numerical simulations of driven magnetohydrodynamic (MHD) turbulence with weak/moderate imposed magnetic fields. The main goal is to clarify dynamics of magnetic field growth. We also investigate the effects of the imposed…

Astrophysics · Physics 2011-02-11 J. Cho , E. Vishniac , A. Beresnyak , A. Lazarian , D. Ryu

In interstellar medium studies, separating ordered and random velocity or magnetic fields is essential for interpreting turbulence in both simulations and observations. We investigate how the choice of averaging scale affects the…

Astrophysics of Galaxies · Physics 2026-04-01 A. Konstantinou , E. Ntormousi , K. Tassis

This work concentrates on the effect of an irrotational forcing on a magnetized flow in the presence of rotation, baroclinicity, shear, or a combination of them. By including magnetic field in the model we can evaluate the occurrence of…

Astrophysics of Galaxies · Physics 2023-09-08 Albert Elias-López , Fabio Del Sordo , Daniele Viganò

Two mechanisms are considered responsible for the turbulence modification due to suspended particles in a turbulent gas-particle suspension. Turbulence augmentation is due to the enhancement of fluctuations by wakes behind particles,…

Fluid Dynamics · Physics 2018-11-19 V. Kumaran , P Muramalla , A. Tyagi , P. S. Goswami

We simulate the dynamics of a single circle microswimmer exploring a disordered array of fixed obstacles. The interplay of two different types of randomness, quenched disorder and stochastic noise, is investigated to unravel their impact on…

Biological Physics · Physics 2020-07-17 Oleksandr Chepizhko , Thomas Franosch

We present and analyze a simplified stochastic $\alpha \Omega -$dynamo model which is designed to assess the influence of additive and multiplicative noises, non-normality of dynamo equation, and nonlinearity of the $\alpha -$% effect and…

Astrophysics · Physics 2009-11-10 Sergei Fedotov , Irina Bashkirtseva , Lev Ryashko

We study the dynamo threshold of a helical flow made of a mean (stationary) plus a fluctuating part. Two flow geometries are studied, either (i) solid body or (ii) smooth. Two well-known resonant dynamo conditions, elaborated for stationary…

Fluid Dynamics · Physics 2009-11-13 Marine Peyrot , Franck Plunian , Christiane Normand

Galactic dynamo models sustained by supernova (SN) driven turbulence and differential rotation have revealed that the sustenance of large scale fields requires a flux of small scale magnetic helicity to be viable. Here we generalize a…

Astrophysics of Galaxies · Physics 2017-05-31 Hongzhe Zhou , Eric G. Blackman

The study of the noise induced effects on the dynamics of a chain molecule crossing a potential barrier, in the presence of a metastable state, is presented. A two-dimensional stochastic version of the Rouse model for a flexible polymer has…

Statistical Mechanics · Physics 2015-05-13 N. Pizzolato , A. Fiasconaro , B. Spagnolo

A generalization to the Kraichnan gaussian, white noise in time model of turbulent velocity field is proposed. The generalization is designed to take into account the effects of stratification in the atmospheric boundary layer by…

Chaotic Dynamics · Physics 2011-04-05 Heikki Arponen

We investigate the large-scale influence of numerical noises as tiny artificial stochastic disturbances on a sustained turbulence. Using the two-dimensional (2D) turbulent Rayleigh-B\'enard (RB) convection as an example, we numerically…

Fluid Dynamics · Physics 2022-09-13 Shijie Qin , Shijun Liao

The gas motions in the intracluster medium (ICM) are governed by stratified turbulence. Stratified turbulence is fundamentally different from Kolmogorov (isotropic, homogeneous) turbulence; kinetic energy not only cascades from large to…

Astrophysics of Galaxies · Physics 2020-03-26 Rajsekhar Mohapatra , Christoph Federrath , Prateek Sharma

We study the effect of confinement on the three-dimensional linear instability of fastly rotating two-dimensional turbulent flows. Using the large scale friction to model the effect of top and bottom boundaries, we study the onset of…

Fluid Dynamics · Physics 2024-03-13 Chandra Shekhar Lohani , Suraj Kumar Nayak , Kannabiran Seshasayanan

We report an experimental investigation on the influence of an external magnetic field on forced 3D turbulence of liquid gallium in a closed vessel. We observe an exponential damping of the turbulent velocity fluctuations as a function of…

Fluid Dynamics · Physics 2015-05-14 Basile Gallet , Michael Berhanu , Nicolas Mordant

Threshold amplitude of disturbance for transition to turbulence in a pipe Poiseuille flow is investigated. Based on the energy gradient theory, we argued that the transition to turbulence depends on magnitudes of the energy gradient of mean…

Fluid Dynamics · Physics 2007-05-23 Hua-Shu Dou , Boo Cheong Khoo , Khoon Seng Yeo

Fluids with internal microstructure like dense suspensions, biological and polymer added fluids, are commonly found in the turbulent regime in many applications. Their flow is extremely difficult to be studied as microstructure complexity…

Fluid Dynamics · Physics 2020-11-11 G. Sofiadis , I. E. Sarris