BB Test

Runs the “BB Test” problem as described in Federrath et al 2010, ApJ, 713, 269, and tests for mass conservation.

The initial conditions include isothermal gas, with the gas having a constant small “external density” outside of the truncation radius. Within the truncation radius, the gas density has the following form:

\(\rho(\phi) = \rho_0 (1 + A \cos(2 \phi)),\)

where \(\rho\) is the gas density, \(\phi\) is the azimuthal angle in the spherical polar coordinate system, \(\rho_0\) is the mean density and \(A\) is the (small) fluctuation amplitude. In addition, the gas rotates around the z-axis as a solid-body.

When the problem is left to run, the gas collapses into a disk, and sink particles form near the center, which accrete gas and merge together.

This test can be executed by running “ctest -R bb_test” in the build directory.

All the files required for running the test can be found in input/bb_test. See input/bb_test/README for further information.