H2020Индивидуална стипендия2020–2022

DynMode · Nonlinear astrophysical dynamos: a novel data-driven approach for interscale dynamics

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2020-09-01 → 2022-08-31
Финансиране от ЕС: 224 934 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Магнитните полета на обекти като звезди и планети се генерират чрез движението на проводими течности. Анализът на тези процеси помага за по-доброто разбиране на физическите свойства на небесните тела и взаимодействието между техните магнитни и поточни полета.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Nonlinear astrophysical dynamos: a novel data-driven approach for interscale dynamics

Many astrophysical objects, such as planets, stars, accretion discs and galaxies possess non-decaying magnetic fields. It is widely believed that these magnetic fields are generated through the action of the magnetohydrodynamic dynamo, a complex nonlinear physical process of magnetic field generation by the motion of conductive fluids. This process depends in a non-trivial way on the structure, chemical composition, stage of evolution of the astrophysical object and its overall energy budget; understanding the dynamo would not only help to describe the magnetic field generation in itself, but also to better understand other properties of planets, stars and accretion disks. There are, however, three long-standing problems in dynamo studies: (i) the physical parameters at which dynamo operates are very hard to achieve experimentally, (ii) full-scale numerical dynamo simulations are not feasible due to enormous range of length and time scales in the flow, and (iii) existing numerical models of turbulent flows with millions of degrees of freedom usually give only a very broad qualitative overview of observed interaction between the magnetic and flow fields. The overall objectives of this project were: to analyze the dynamo data from existing numerical models in various geometries with data-driven methods; to identify and extract spatial patterns (modes) corresponding to dynamically relevant components of the dynamo flow; and to relate the temporal evolution of the spatial components, or modal basis, in data-driven reduced-order models that would describe the nonlinear interactions between magnetic and flow fields.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Magnetic fields are ubiquitous in the Universe, and are thought to play a key role in evolution of stars, planets, accretion discs and black holes. Although it is generally accepted that these fields are created by the motions of conductive fluids – hydromagnetic dynamos, there is no ab initio predictive theory for their origin and evolution. Because of nonlinear coupling between magnetic field and fluid flow, and also due to extreme parameters of astrophysical objects, dynamos arise from interactions of the flow and field on extremely vast range of space and time scales. This limits the utility of computational approaches.The DynMode project seeks to elucidate the nature of interscale nonlinear interactions using the novel data-based approach from dynamical systems theory, and to create nonlinear reduced-order models of astrophysical dynamos that represent dynamics on large, intermediate and small scales. This is crucial for our understanding of the operation of astrophysical dynamos. During this Fellowship, we will decompose the data of dynamo flows into dynamically relevant blocks (modes), identify principal nonlinear dynamics and energy exchange among those blocks, and create a reduced-order dynamo model by projecting the flow onto them. By analyzing data sets from self-sustained and convective-driven dynamos in different geometries, we will also address the question of intrinsic dynamo features as compared to influence of secondary physical effects and flow geometry. This approach, applied for the first time in dynamo research, will explain interactions between small-scale and large-scale dynamos and their nonlinear saturation, as well as physics of weak and strong geodynamos. The project, bringing together physical modelling of the dynamos, study of the flow and magnetic field structures, and innovative data-driven strategy, has a potential to significantly advance the current understanding of dynamos, and impact wider research community in fluid dynamics

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITY OF LEEDS · LeedsКоординаторОбединеното кралство