The HECToR Service is now closed and has been superceded by ARCHER.

Micromagnetic modelling of naturally occurring magnetic mineral systems

This Distributed Computational Science and Engineering (dCSE) project is to port a fully parallel version of the MicroMag to HECToR. MicroMag utilises an unstructured finite element model and is used for simulations of the magnetic properties of minerals and the stability of the related palaeomagnetic recordings. MicroMag can be used to determine how the magnetic properties of minerals change with the mineral microstructure over a range of real time scales. This project will enable much larger scale simulations and help theoretical results to compare with and extend experimental observations.

The key aims of the project are:

  • Develop a Semi-Parallel Implementation without optimised unstructured partitioning. This excludes parallelisation of the main component fields.
  • Implement a fully Parallel version of MicroMag. Including parallelisation of the main component fields and optimised unstructured partitioning.

The individual achievements of the project are summarised below:

  • The CVODE time solver was implemented and a 1.64 times speed up was achieved for the serial calculations.
  • Upon more in depth analysis, it was realised that the Semi-Parallel Implementation was not going to work. In order to acheive the original project objectives it was decided to implement calls to the PETSc library for the remaining project time.
  • MicroMag now uses the PETSc parallel data structures. These are utilised so that although they are built up in serial, each time iteration is performed in parallel.
  • An external bug in the PETSc interface to the implicit time iterative solver CVODE was discovered. A patch to fix the bug was issued by the main developers and calls to CVODE were implemented.
  • Testing and benchmarking of up to 16 nodes (384 cores) of the XE6, phase 2b machine revealed a subtle bug in the construction of one of the matrices, and some poor scaling performance. Further work is required to fix the bug, and investigate the cause of the poor performance.

    • Please see PDF or HTML for a report which summarises this project.