Particle-Assisted MHD
Ilja Honkonen
Finnish Meteorological Institute
Thanks to Alex Glocer, Lutz Rastätter, NASA Postdoctoral Program
Contents
- Model at CCMC
- Intro to particle-assisted magnetohydrodynamics
- Current results & developments
Model at CCMC, notable features
- Currently only MHD part of PAMHD
- Free and open source (github.com/iljah/pamhd)
- Dynamic (point & click) run submission interface
- Can start from existing run configuration
- Flexible initial & boundary conditions
- Geometries: box, sphere
- Boundaries: value, copy
- Values: math expression with r, t, lat, lon, ...
- Arbitrary number of magnetic 3d dipoles
- 2d line dipole not at CCMC yet
Example runs at CCMC 1
Pressure in "global" (no ionosphere) MHD simulation of Earth's magnetosphere (results for northward IMF on
left and southward IMF on
right)
Example runs at CCMC 2
Logarithmic density in 2d simulation of interaction of magnetospheres of Jupiter and Saturn (
description,
results)
Example runs at CCMC 2
Closer look at density around Saturn's magnetosphere
Example runs at CCMC 3
Jet injection
(2d, after
CSRCR2012-01)
with
value boundaries in red and
copy boundaries in blue
showing density (
results)
PAMHD intro
- Two-population MHD
- Solution calculated from total plasma
- Solution assigned to populations by mass fraction
- Particles overwrite one MHD population after every step
- Any hybrid kinetic solution method applicable
- Any MHD solution method applicable
Two-population MHD
Graphically, flux calcualtion changed from:
to:
Can discard MHD solution of any population(s) and replace with other solution(s)
PAMHD two-stream test 1
Hybrid particle-in-cell, initial and final states:
PAMHD two-stream test 1
Upper population partially replaced by MHD:
PAMHD two-stream test 2
Quantitative effect, parallel (to tube) E squared:
PAMHD two-stream test 3
Quantitative effect, parallel (to tube) E squared:
PAMHD "global" msphere
Particle temperature
- Before 3600 s: MHD
- After 3600 s: 10% SW mass = 3 part / 1 Re cell
PAMHD "global" msphere
Last currently available particle temperature
- Before 3600 s: MHD
- After 3600 s: 10% SW mass = 3 part / 1 Re cell
PAMHD "global" msphere
Total pressure
- Before 3600 s: MHD
- After 3600 s: 10% SW mass = 3 part / 1 Re cell
PAMHD "global" msphere
Last currently available total pressure
- Before 3600 s: MHD
- After 3600 s: 10% SW mass = 3 part / 1 Re cell