Self sImilar SoluTions foR yoU and Me (SISTRUM)

A percussion instrument and also a repository of Python 3.x self-similar solutions that I've needed, and so written. Contributions welcome. A minimally working environment file is provided.

Sedov-Taylor blast wave

Self-similar solution for the Sedov-Taylor non-relativistic blast wave. Based on work by James R. Kamm and Kamm & Timmes. Supports density profiles of the from $\rho(r) = \rho_{0} r^{-w}$. Supports planar (j = 1), cylindrical (j = 2), and spherical (j = 3) geometries. There are constraints on the density power law index. See the paper.

Usage

from sedov import Sedov
sedov_solution = Sedov(j, w, E, rho0, gamma, t_end, r_model)
r = sedov.r
rho_sol = sedov.rho_sol
# plot away

Testing

We include test.py that implements tests for the Sedov-Taylor solutions. For this test we set up a grid in geometry, density power law space. To test, we download and compile the sedov3 code provided by Frank Timmes. We compare our solution to his. This is triggered on every push / PR, and you can invoke by, e.g., pytest src/test.py. In the future it should test other solutions.

TODO:

• Some solutions, such as velocity, still need implementation.

Blandford McKee Blast Wave

See the paper. Computes post-shock similarity variables and pressure, etc. Assumes density profiles of the from $\rho(r) \propto r^{-k}$.

Usage

from bmk import BMK
bmk_solution = BMK(k, W, t, P0, t_shock, rad)
rad = bmk_solution.r
pressure = bmk_solution.p # see also bmk_solution.f for similarity variable

Code Style

Code linting and formatting is done with ruff. Rules are listed in ruff.toml. To check all python in the current directory, you may ruff .. To format a given file according to ruff.toml, run ruff format file.py. Checks for formatting are performed on each push / PR. We (try to) adhere to semantic versioning and conventional commits.