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Related papers: Simulating Gyrokinetic Microinstabilities in Stell…

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We present a new three-dimensional general-relativistic hydrodynamic evolution scheme coupled to dynamical spacetime evolutions which is capable of efficiently simulating stellar collapse, isolated neutron stars, black hole formation, and…

High Energy Astrophysical Phenomena · Physics 2013-09-23 C. Reisswig , R. Haas , C. D. Ott , E. Abdikamalov , P. Moesta , D. Pollney , E. Schnetter

The static linearity performance metrics of the GFET transconductor are studied and modeled. Closed expressions are proposed for second and third order harmonic distortion (HD2, HD3), second and third order intermodulation distortion…

Mesoscale and Nanoscale Physics · Physics 2014-09-09 Saul Rodriguez , Anderson Smith , Sam Vaziri , Mikael Ostling , Max C. Lemme , Ana Rusu

We give a detailed and improved presentation of our recently proposed formalism for non-linear perturbations in cosmology, based on a covariant and fully non-perturbative approach. We work, in particular, with a covector combining the…

Astrophysics · Physics 2009-11-13 David Langlois , Filippo Vernizzi

This work features the optimization of a Permanent Magnet Synchronous Motor using 2D nonlinear simulations in an Isogeometric Analysis framework. The rotor and stator designs are optimized for both geometric parameters and surface shapes…

Optimization and Control · Mathematics 2026-05-19 Michael Wiesheu , Theodor Komann , Melina Merkel , Sebastian Schöps , Stefan Ulbrich , Idoia Cortes Garcia

The majority of nuclei available for study in solid state Nuclear Magnetic Resonance have half-integer spin $I > 1/2 $, with corresponding electric quadrupole moment. As such, they may couple with a surrounding electric field gradient. This…

Materials Science · Physics 2009-05-19 William J. Brouwer , Michael C. Davis , Karl T. Mueller

This work studies the effects of a through-flow on two-dimensional electrohydrodynamic (EHD) flows of a dielectric liquid confined between two plane plates, as a model problem to further our understanding of the fluid mechanics in the…

Fluid Dynamics · Physics 2022-02-03 Zhe Feng , Dongdong Wan , Bo-Fu Wang , Mengqi Zhang

Over the past decades, multiple gyrokinetic codes have shown to be able to simulate turbulence and associated transport in the core of Tokamak devices. However, their application to the edge and scrape-off layer (SOL) region presents…

We present preliminary results from multidimensional numerical studies of pair instability supernova (PSN), studying the fluid instabilities that occur in multiple spatial dimensions. We use the new radiation-hydrodynamics code, CASTRO, and…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Ke-Jung Chen , Alexander Heger , Ann Almgren

We consider spectral mixed discontinuous Galerkin finite element discretizations of the Lam\'e system of linear elasticity in polyhedral domains in $\mathbb{R}^3$. In order to resolve possible corner, edge, and corner-edge singularities,…

Numerical Analysis · Mathematics 2019-08-14 Thomas P. Wihler , Marcel Wirz

The periodic standing wave approach to binary inspiral assumes rigid rotation of gravitational fields and hence helically symmetric solutions. To exploit the symmetry, numerical computations must solve for ``helical scalars,'' fields that…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Christopher Beetle , Benjamin Bromley , Richard H. Price

One metric for comparing confinement properties of different magnetic fusion energy configurations is the linear critical gradient of drift wave modes. The critical gradient scale length determines the ratio of the core to pedestal…

Plasma Physics · Physics 2013-03-08 J. A. Baumgaertel , G. W. Hammett , D. R. Mikkelsen

Nonlinear gyrokinetics provides a suitable framework to describe short-wavelength turbulence in magnetized laboratory and astrophysical plasmas. In the electrostatic limit, this system is known to exhibit a free energy cascade towards small…

Plasma Physics · Physics 2014-08-07 S. S. Cerri , A. Bañón Navarro , F. Jenko , D. Told

Many stellarator coil design problems are plagued by multiple minima, where the locally optimal coil sets can sometimes vary substantially in performance. As a result, solving a coil design problem a single time with a local optimization…

Computational Physics · Physics 2024-05-22 Andrew Giuliani

A variety of gravitational dynamics problems in asymptotically anti-de Sitter (AdS) spacetime are amenable to efficient numerical solution using a common approach involving a null slicing of spacetime based on infalling geodesics,…

High Energy Physics - Theory · Physics 2016-05-24 Paul M. Chesler , Laurence G. Yaffe

A method is demonstrated to rapidly calculate the shapes and properties of quasi-axisymmetric and quasi-helically symmetric stellarators. In this approach, optimization is applied to the equations of magnetohydrodynamic equilibrium and…

Plasma Physics · Physics 2023-01-04 Matt Landreman

The implementation of a resistive-wall extension to the non-linear MHD-code JOREK via a coupling to the vacuum-field code STARWALL is presented along with first applications and benchmark results. Also, non-linear saturation in the presence…

Maximising particle and energy confinement is crucial for achieving the sustained burning plasma conditions necessary to realise fusion energy. For stellarator reactors, one proposed strategy for avoiding destructive instabilities is to…

Plasma Physics · Physics 2025-12-30 Adelle M. Wright , Benjamin J. Faber

Even though compressible plasma turbulence is encountered in many astrophysical phenomena, its effect is often not well understood. Furthermore, direct numerical simulations are typically not able to reach the extreme parameters of these…

Fluid Dynamics · Physics 2016-07-27 P. Grete , D. G. Vlaykov , W. Schmidt , D. R. G. Schleicher

We present our first successful numerical results of 3D general relativistic simulations in which the Einstein equation as well as the hydrodynamic equations are fully solved. This paper is especially devoted to simulations of test problems…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Masaru Shibata

This paper describes a new code for simulating astrophysical plasmas that solves a hybrid model composed of gyrokinetic ions (GKI) and an isothermal electron fluid (ITEF) [A. Schekochihin et al., Astrophys. J. Suppl. \textbf{182}, 310…

Plasma Physics · Physics 2018-02-05 Y. Kawazura , M. Barnes