English
Related papers

Related papers: Mode analysis of numerical geodynamo models

200 papers

The upcoming DRESDYN (DREsden Sodium facility for DYNnamo and thermohydraulic studies) precession experiment will test the possibility to achieve magnetohydrodynamic dynamo action solely driven by precession. Here, after the description of…

Fluid Dynamics · Physics 2023-01-20 F. Pizzi , A. Giesecke , J. Simkanin , V. Kumar , T. Gundrum , F. Stefani

Dynamic simulators model systems evolving over time. Often, it operates iteratively over fixed number of time-steps. The output of such simulator can be considered as time series or discrete functional outputs. Metamodeling is an e ective…

Applications · Statistics 2013-04-04 Ekaterina Sergienko , Fabrice Gamboa , Daniel Busby

We reveal and analyze an efficient magnetic dynamo action due to precession-driven hydrodynamic turbulence in the local model of a precessional flow, focusing on the kinematic stage of this dynamo. The growth rate of magnetic field…

Fluid Dynamics · Physics 2024-05-08 V. Kumar , F. Pizzi , G. Mamatsashvili , A. Giesecke , F. Stefani , A. J. Barker

The normal modes and relaxation rates of weak colloidal gels are investigated in computations employing different models of the hydrodynamic interactions between colloids. The eigenspectrum is computed for freely draining,…

Fluid Dynamics · Physics 2018-01-17 Zsigmond Varga , James W. Swan

Our understanding of large-scale magnetic fields in stellar radiative zones remains fragmented and incomplete. Such magnetic fields, which must be produced by some form of dynamo mechanism, are thought to dominate angular-momentum…

Solar and Stellar Astrophysics · Physics 2022-09-28 Valentin Skoutnev , Jonathan Squire , Amitava Bhattacharjee

Computational heliophysics has shed light on the fundamental physical processes inside the Sun, such as the differential rotation, meridional circulation, and dynamo-generation of magnetic fields. However, despite the substantial advances,…

Solar and Stellar Astrophysics · Physics 2023-01-25 A. G. Kosovichev , G. Guerrero , A. M. Stejko , V. V. Pipin , A. V. Getling

We examine kinematic dynamo action driven by an axisymmetric large scale flow that is superimposed with an azimuthally propagating non-axisymmetric perturbation with a frequency $\omega$. Although we apply a rather simple large scale…

Fluid Dynamics · Physics 2017-05-23 Andre Giesecke , Frank Stefani , Johann Herault

Currently, it is challenging to investigate aneurismal hemodynamics based on current in-vivo data such as Magnetic Resonance Imaging or Computed Tomography due to the limitations in both spatial and temporal resolutions. In this work, we…

Fluid Dynamics · Physics 2024-10-17 Thien-Tam Nguyen , Davina Kasperski , Phat Kim Huynh , Trung Quoc Le , Trung Bao Le

External influences such as traffic and environmental factors induce vibrations in structures, leading to material degradation over time. These vibrations result in cracks due to the material's lack of plasticity compromising structural…

Machine Learning · Computer Science 2024-07-02 Melanie Schaller , Daniel Schlör , Andreas Hotho

This paper is a continuation and an extension of our recent work [13] on the identification of magnetized anomalies using geomagnetic monitoring, which aims to establish a rigorous mathematical theory for the geomagnetic detection…

Analysis of PDEs · Mathematics 2019-09-04 Youjun Deng , Jinhong Li , Hongyu Liu

Magnetic fields have been constrained at the surface of several massive and intermediate-mass stars, but their origin and properties in deep stellar radiative interiors are still debated, despite recent detections in the core of some red…

Solar and Stellar Astrophysics · Physics 2026-02-03 Florentin Daniel , Ludovic Petitdemange , Charly Pinçon , Kévin Belkacem , Bruno Longo , Christophe Gissinger

Understanding the origin and evolution of magnetic fields on cosmological scales opens up a window into the physics of the early Universe. Numerical simulations of such fields require a careful treatment to faithfully solve the equations of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Nikyta Shchutskyi , Matthieu Schaller , Orestis A. Karapiperis , Federico A. Stasyszyn , Axel Brandenburg

Dynamo action owing to helically forced turbulence and large-scale shear is studied using direct numerical simulations. The resulting magnetic field displays propagating wave-like behavior. This behavior can be modelled in terms of an…

Astrophysics · Physics 2011-02-11 P. J. Käpylä , A. Brandenburg

The conventional magnetic induction equation that governs hydromagnetic dynamo action is transformed into an equivalent integral equation system. An advantage of this approach is that the computational domain is restricted to the region…

Astrophysics · Physics 2009-06-23 Mingtian Xu , Frank Stefani , Gunter Gerbeth

This work introduces a theoretical extension of the characteristic mode formulation for analysing the vertical electric dipole lying above a lossy dielectric half-space. As the conventional characteristic formulation fails to maintain the…

Signal Processing · Electrical Eng. & Systems 2020-09-23 Sandip Ghosal , Arijit De , Raed M. Shubair , Ajay Chakrabarty

Modern problems in magnetization dynamics require more and more the numerical determination of the spin-wave spectra and -dispersion in magnetic systems where analytic theories are not yet available. Micromagnetic simulations can be used to…

Mesoscale and Nanoscale Physics · Physics 2021-11-24 Lukas Körber , Attila Kákay

We have performed numerical simulations of the kinematic induction equation in order to examine the dynamo efficiency of an axisymmetric von-K\'arm\'an-like flow subject to time-dependent non-axisymmetric velocity perturbations. The…

Fluid Dynamics · Physics 2015-06-11 Andre Giesecke , Frank Stefani , Javier Burguete

Using the non-linear mean-field dynamo models we calculate the magnetic cycle parameters, like the dynamo cycle period, the amplitude of the total magnetic energy, and the Poynting flux luminosity from the surface for the solar analogs with…

Solar and Stellar Astrophysics · Physics 2021-01-27 V. V. Pipin

The mean-field dynamo model is employed to study the non-linear dynamo regimes in a fully convective star of mass 0.3$M_{\odot}$ rotating with period of 10 days. For the intermediate value of the parameter of the turbulent magnetic Prandl…

Solar and Stellar Astrophysics · Physics 2017-02-01 V. V. Pipin

A data-driven analysis method known as dynamic mode decomposition (DMD) approximates the linear Koopman operator on projected space. In the spirit of Johnson-Lindenstrauss Lemma, we will use random projection to estimate the DMD modes in…

Machine Learning · Computer Science 2021-11-09 Sudam Surasinghe , Erik M. Bollt