Numerical projects
PIERNIK MHD
Project website
Code repository
MECHANIC
Mechanic is an advanced numerical environment whose main task is to assist in running long-term numerical simulations in computational clusters. The code is based on MPI technology (Message Passing Interface), and communication between processors takes place within a so-called farm. The code’s structure allows for complete separation of the layers of configuration, communication and data recording (so-called core), from a the actual numerical task (numerical module). The software provides sophisticated API (Application Programming Interface), thanks to which a user can easily implement numerical problems. Unlike the existing codes form the family, so-called task management systems (such as Condor, Workqueue), Mechanic tries to standardize the layer of communication, configuration and data recording.
The code is written in C language and is available under the BSD license.
The code’s main advantages include:
- Separation of the configuration, communication and data recording layers
- Clear API
- Automatic creation of backup copies during simulation process
- Non-blocking communication between processors
- Data recording in open HDF5 format
Group members: prof. dr hab. Krzysztof Goździewski, mgr Mariusz Słonina, dr Cezary Migaszewski
Project website
Code repository
INHOMOG
The inhomog library calculates average cosmological expansion. This particular package contains an example front end program that uses the biscale_partition routines of the inhomog library, illustrating effective scale factor evolution in a universe with a T3 spatial section that is divided into two complementary domains. The inhomog library provides Raychaudhuri integration of cosmological domain-wise average scale factor evolution using an analytical formula for kinematical backreaction Q_D evolution. The library routine lib/Omega_D_precalc.c is callable by RAMSES using ramses-scalav. You may use this front-end program for command-line investigation of the role of virialisation as a potential replacement for dark energy (see Roukema 2017, arXiv:1706.06179). This description and the code itself are licensed under the GNU GPL.
Group members: dr hab. Boudewijn Roukema, prof. UMK, dr Jan Ostrowski
RAMSES-SCALAV
The ramses-scalav package is an extension of RAMSES that functions as a front end to the DTFE and inhomog libraries to evolve cosmological initial conditions generated by, for example, a free-licensed program such as mpgrafic. The aim is to calculate the effective (global) scale factor evolution as the volume average of domain-wise scale factor a_D evolution based on integrating the Raychaudhuri equation. This should be relativistically more realistic than the standard approach of inserting an externally calculated FLRW scale factor evolution. The long term aim is to have this extension accepted into the rteyssie RAMSES master branch following discussion within the RAMSES team, initially as a patch, and possibly later into the core directories. This description and the code itself are licensed under Cecill. The main article with scientific details is Roukema (2017, arXiv:1706:06179).
Group members: dr hab. Boudewijn Roukema, prof. UMK, dr Jan Ostrowski