The Llama code is a 3-dimensional multiblock infrastructure for Cactus based on Carpet. It provides different patch systems that cover the simulation domain by a set of overlapping patches. Each of these patches has local cooordinates with a well-defined relation to global Cartesian coordinates. Information between the different patches is communicated via interpolation in the overlap zones.
Here we show an example evolution of a wave equation on a Kerr background using the "Thornburg2004nc" patch-system, consisting of 90 degree by 90 degree wedges centred on each of the +x, -x, +y, -y, +z, -z coordinate axes. This provides a complete covering of a region between rmin and rmax with smooth inner and outer boundaries. The initial data is an l=2, m=2 spherical harmonic in the angular directions, and a Gaussian in the radial direction. An alternative patch system, "Thornburg2004", adds a cubical patch enclosing r < rmin in which standard Carpet box-in-box mesh refinement can be employed. This is used in the GW150914 gravitational wave gallery example.
We ask that if you make use of the Llama code, then please cite Llama, the Einstein Toolkit, the Carpet mesh-refinement driver and Cactus.
|Submission command||simfactory/bin/sim create-submit Kerr-Schild_Multipole --parfile arrangements/Llama/LlamaWaveToy/par/Kerr-Schild_Multipole.par|
|Total memory||800 MB|
|Run time||About 5 minutes using 8 MPI tasks and 8 cores on an HPC; or about 10 minutes on two laptop cores|
This example was last tested on 16-May-2021.
If the file structure is different than expected in the saved *.session files above, the following VisIt directions might help: