Table of contents
MHD Simulations with the
NIMROD Code
The NIMROD Team
Modern Tokamak
Discharges Have Rich Magnetic Behavior
Resistive MHD is
Inadequate for Explaining Modern Discharges
What is Needed?
NIMROD Uses "Extended
MHD"
Two-Fluid Equations Are
Numerically Challenging
Temporal Advance Uses
Semi-Implicit Method
Finite-Elements Used for
Flexible Spatial Discretization
NIMROD Also Has
Flexibility in Finite-Element Basis
Higher-Order Elements
Useful For Shaped Geometries
Toroidal Direction Uses
Fourier Decomposition
Spheromak Simulations
Illustrate Flexibility of NIMROD
Flux Amplification
Occurs Due to Dynamo Process
Axisymmetric components
show relaxation towards Taylor state
Despite Taylor
Relaxation, Fields Largely Chaotic
Dominant Mode Saturated
n=1 Pinch Instability
Decaying Spheromaks
Form Flux Surfaces
Vacuum Region Necessary
for Correct Stability Boundary
NIMROD Models Vacuum As
Very Resistive Plasma
Model Gives Good Linear
Convergence
Eigenfunctions Converge
For Increasing Resistivity
Status of Vacuum
Implementation
Summary
Summary
(continued)
NIMROD is for the
Community
|
Author: Scott Kruger
E-mail: krugers@saic.com
Homepage: http://www.nimrodteam.org/
|