# Parallel computing resources for the UK MHD community

Lead Research Organisation:
University of Leeds

Department Name: Applied Mathematics

### Abstract

Virtually all material in the universe consists of an ionised gas called a plasma. Plasmas conduct electricity and interact with magnetic fields, producing many physical phenomena not easily reproduced in laboratories on Earth. The large-scale behaviour of these plasmas can be predicted by using a known set of complicated mathematical equations, called the equations of Magnetohydrodynamics (MHD). The solutions of MHD equations can describe the behaviour of plasmas in which collisions dominate the physical processes, such as (i) the generation of magnetic fields through a process known as dynamo action, (ii) the release of a staggering amount of magnetic energy in a large solar flare by magnetic reconnection, (iii) the small scale chaotic motions of turbulence in a magnetised plasma, (iv) the fact that solar atmosphere is much hotter than the solar surface and (v) the way in which gigantic eruptions of solar plasma interact with the Earth's magnetic field to produce the Aurora. When collisional effects are weak, in low-density plasmas and in problems involving short length-scales, the more fundamental kinetic equations must be solved. However, the solution of both sets of equations require extremely large computers and the best way is to link several hundred computers together and get them all working on a fraction of the large problem. These computers are called parallel computers. The UK effort in this research area is at the forefront of the worldwide effort to understand how the Sun, the Solar System and astrophysical plasmas work. While this work is essentially theoretical, it is driven by the observations of the present fleet of solar and astrophysical ground and space-based observatories.

## People |
## ORCID iD |

Samuel Falle (Principal Investigator) |

### Publications

Aluzas R
(2012)

*Numerical simulations of shocks encountering clumpy regions Simulations of shocks encountering clumpy regions*in Monthly Notices of the Royal Astronomical Society
Arber T
(2009)

*THERMAL FRONTS IN FLARING MAGNETIC LOOPS*in The Astrophysical Journal
Barker A
(2012)

*Magnetic buoyancy instabilities in the presence of magnetic flux pumping at the base of the solar convection zone Magnetic buoyancy and flux pumping*in Monthly Notices of the Royal Astronomical Society
Barker A
(2016)

*Non-linear tides in a homogeneous rotating planet or star: global simulations of the elliptical instability*in Monthly Notices of the Royal Astronomical Society
Barkov M
(2010)

*Close binary progenitors of gamma-ray bursts*in Monthly Notices of the Royal Astronomical Society
Botha G
(2012)

*OBSERVATIONAL SIGNATURES OF THE CORONAL KINK INSTABILITY WITH THERMAL CONDUCTION*in The Astrophysical Journal
Botha G
(2011)

*CHROMOSPHERIC RESONANCES ABOVE SUNSPOT UMBRAE*in The Astrophysical Journal
Botha G
(2010)

*Thermal conduction effects on the kink instability in coronal loops*in Astronomy & Astrophysics
Bowker J
(2014)

*Incorporating velocity shear into the magneto-Boussinesq approximation*in Geophysical & Astrophysical Fluid Dynamics
Burge C
(2016)

*Ambipolar diffusion regulated collapse of filaments threaded by perpendicular magnetic fields*in Astronomy & AstrophysicsDescription | The computations carried out with this equipment has shown us how magnetic fields play a crucial role in many astrophysical objects such as stars, accretion discs and galaxies. |

Exploitation Route | Our work has stimulated others to use many of our computational techniques to study astrophysical magnetic fields. |

Sectors | Aerospace, Defence and Marine,Energy,Environment |

Description | The numerical methods that have been developed during the project have been used in and industrial application: safety assessment of liquid carbon dioxide transport. |

First Year Of Impact | 2012 |

Sector | Aerospace, Defence and Marine,Energy,Environment |

Impact Types | Cultural,Economic |