Simulated annealing for three-dimensional low-beta reduced MHD equilibria in cylindrical geometry
نویسندگان
چکیده
Simulated annealing (SA) is applied for three-dimensional (3D) equilibrium calculation of ideal, low-beta reduced MHD in cylindrical geometry. The SA is based on the theory of Hamiltonian mechanics. The dynamical equation of the original system, low-beta reduced MHD in this study, is modified so that the energy changes monotonically while preserving the Casimir invariants in the artificial dynamics. An equilibrium of the system is given by an extremum of the energy, therefore SA can be used as a method for calculating ideal MHD equilibrium. Previous studies demonstrated that the SA succeeds to lead to various MHD equilibria in two-dimensional rectangular domain. In this paper, the theory is applied to 3D equilibrium of ideal, low-beta reduced MHD. An example of equilibrium with magnetic islands, obtained as a lower energy state, is shown. Several versions of the artificial dynamics are developed that can effect smoothing. The smoothing effect is examined in the numerical results.
منابع مشابه
Development and Parallelization of Gyrokinetic PIC Code for MHD Simulation
In order to simulate global magnetogydrodynamic phenomena in tokamaks, a new gyrokinetic PIC (particle-in-cell) code, Gpic-MHD, is developed. Gpic-MHD is written in cylindrical geometry and has single-helicity (two-dimensional) version and multi-helicity (three-dimensional) version. The kinetic internal kink mode is successfully simulated and compared with the results of gyro-reduced-MHD (GRM) ...
متن کاملEigenvalue problems for Beltrami fields arising in a three-dimensional toroidal magnetohydrodynamic equilibrium problem
A generalized energy principle for finite-pressure, toroidal magnetohydrodynamic MHD equilibria in general three-dimensional configurations is proposed. The full set of ideal-MHD constraints is applied only on a discrete set of toroidal magnetic surfaces invariant tori , which act as barriers against leakage of magnetic flux, helicity, and pressure through chaotic field-line transport. It is ar...
متن کاملNon-ideal MHD ballooning modes in three-dimensional configurations
A linear stability theory of non-ideal MHD ballooning modes is investigated using a two fluid model for arbitrary three-dimensional electron-ion plasmas. Resistive-inertia ballooning mode (RIBM) eigenvalues and eigenfunctions are calculated for a variety of equilibria including axisymmetric shifted circular geometry (s − α model) and configurations of interest to the Helically Symmetric Stellar...
متن کاملMHD Three-Dimensional Stagnation-Point Flow and Heat Transfer of a Nanofluid over a Stretching Sheet
In this study, the three-dimensional magnetohydrodynamic (MHD) boundary layer of stagnation-point flow in a nanofluid was investigated. The Navier–Stokes equations were reduced to a set of nonlinear ordinary differential equations using a similarity transform. The similarity equations were solved for three types of nanoparticles: copper, alumina and titania with water as the base fluid, to inve...
متن کاملUnstable magnetohydrodynamical continuous spectrum of accretion disks A new route to magnetohydrodynamical turbulence in accretion disks
Context. We present a detailed study of localised magnetohydrodynamical (MHD) instabilities occuring in two– dimensional magnetized accretion disks. Aims. We model axisymmetric MHD disk tori, and solve the equations governing a two–dimensional magnetized accretion disk equilibrium and linear wave modes about this equilibrium. We show the existence of novel MHD instabilities in these two–dimensi...
متن کامل