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Related papers: Supercriticality to subcriticality in dynamo trans…

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When an interacting many-body system, such as a magnet, is driven in time by an external perturbation, such as a magnetic field,the system cannot respond instantaneously due to relaxational delay. The response of such a system under a…

Statistical Mechanics · Physics 2009-10-31 Bikas K Chakrabarti , Muktish Acharyya

We carry out systematic and high-resolution studies of dynamo action in a shell model for magnetohydrodynamic (MHD) turbulence over wide ranges of the magnetic Prandtl number $Pr_{\rm M}$ and the magnetic Reynolds number $Re_{\rm M}$. Our…

Chaotic Dynamics · Physics 2010-03-23 Ganapati Sahoo , Dhrubaditya Mitra , Rahul Pandit

Experiments (Mullin and Kreswell, 2005) show that transition to turbulence can start at Reynolds numbers lower than it is predicted by the linear stability analysis - the subcritical transition to turbulence. To explain these observations…

Fluid Dynamics · Physics 2008-07-08 K. Y. Volokh

A few paradigmatic one-dimensional lattice-statistical spin models have recently attracted a vigorous scientific interest owing to their peculiar thermodynamic behavior, which is highly reminiscent of a temperature-driven phase transition.…

Statistical Mechanics · Physics 2020-08-17 Jozef Strecka

Many physical systems, including classical fluids, present in their phase diagram the competition between two phases that are separated by a line of first-order phase transitions which terminates at a so-called critical point. Despite…

High Energy Physics - Theory · Physics 2025-04-29 Zi-Qiang Zhao , Zhang-Yu Nie , Jing-Fei Zhang , Xin Zhang , Matteo Baggioli

We perform numerical simulation of dynamo with magnetic Prandtl number $\mathrm{Pm} =0.2$ on $1024^3$ grid, and compute the energy fluxes and the shell-to-shell energy transfers. These computations indicate that the magnetic energy growth…

Fluid Dynamics · Physics 2015-06-26 Rohit Kumar , Mahendra K. Verma , Ravi Samtaney

Spin crossover molecules have recently emerged as a family of compounds potentially useful for implementing molecular spintronics devices. The calculations of the electronic properties of such molecules is a formidable theoretical challenge…

Materials Science · Physics 2015-06-04 Andrea Droghetti , Dario Alfe' , Stefano Sanvito

Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale by electromotive force (e.m.f.) in the…

Earth and Planetary Astrophysics · Physics 2011-09-29 Giuseppina Nigro , Pierlugi Veltri

Recently, we have proposed a new dynamic line on the phase diagram in the supercritical region. Crossing this line corresponds to the radical changes of the fluid properties. Here, we focus on the dynamics of model Lennard-Jones and…

Soft Condensed Matter · Physics 2015-06-16 V. V. Brazhkin , Yu. D. Fomin , A. G. Lyapin , V. N. Ryzhov , E. N. Tsiok , Kostya Trachenko

We investigate the dynamo problem in the limit of small magnetic Prandtl number ($\Pm$) using a shell model of magnetohydrodynamic turbulence. The model is designed to satisfy conservation laws of total energy, cross helicity and magnetic…

Fluid Dynamics · Physics 2007-05-23 Rodion Stepanov , Franck Plunian

Numerous study on natural and man made systems including rotating convection report the phenomena of supercritical and subcritical transitions from one state to another with the variation of relevant control parameters. However, the…

Fluid Dynamics · Physics 2024-04-01 Sutapa Mandal , Snehashish Sarkar , Pinaki Pal

The growth of a large-scale magnetic field in the Sun and stars is usually possible when the dynamo number (D) is above a critical value Dc. As the star ages, its rotation rate and thus D decrease. Hence, the question is how far the solar…

Solar and Stellar Astrophysics · Physics 2025-01-07 Sanket Wavhal , Pawan Kumar , Bidya Binay Karak

The main objective of this article is to study both dynamic and structural transitions of the Taylor-Couette flow, using the dynamic transition theory and geometric theory of incompressible flows developed recently by the authors. In…

Mathematical Physics · Physics 2010-05-13 Tian Ma , Shouhong Wang

The dynamics of supercritical fluids, a state of matter beyond the gas-liquid critical point, changes from diffusive to oscillatory motions at high pressure. This transition is believed to occur across a locus of thermodynamic states called…

Statistical Mechanics · Physics 2018-10-16 Tae Jun Yoon , Min Young Ha , Emanuel A. Lazar , Won Bo Lee , Youn-Woo Lee

For a cylindrical superconductor surrounded by a normal material, we discuss transition to the normal phase of stable, locally stable and critical configurations. Associated with those phase transitions, we define critical magnetic fields…

Analysis of PDEs · Mathematics 2008-12-19 S. Fournais , A. Kachmar

Effect of disorder in metallic thin film is examined as a possible mechanism of the Superconductor-Insulator (S-I) transition. The critical value of disorder corresponding to the transition point is found analytically by using…

Superconductivity · Physics 2007-05-23 Masahiko Kasuga , Susumu Kurihara

We report a series of numerical simulations showing that the critical magnetic Reynolds number Rm_c for the nonhelical small-scale dynamo depends on the Reynolds number Re. Namely, the dynamo is shut down if the magnetic Prandtl number…

Astrophysics · Physics 2009-11-16 A. A. Schekochihin , S. C. Cowley , J. L. Maron , J. C. McWilliams

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

The existence of a dynamo effect in a simplified magnetohydrodynamic model of turbulence is considered when the magnetic Prandtl number approaches zero or infinity. The magnetic field is interacting with an incompressible…

Chaotic Dynamics · Physics 2009-11-11 Heikki Arponen , Peter Horvai

Hydrodynamic and magnetohydrodynamic convective attractors in three-dimensional rotating Rayleigh-B\'enard convection are studied numerically by varying the Taylor and Rayleigh numbers as control parameters. First, an analysis of…

Fluid Dynamics · Physics 2024-09-23 Dalton N. Oliveira , Roman Chertovskih , Erico L. Rempel , Francis F. Franco