History & Contributions

Contributions

Ulula is developed and maintained by Benedikt Diemer, University of Maryland. I am grateful for the following contributions:

  • Code to create gif movies was contributed by Calvin Osinga.

  • The computation of annulus-square overlaps in radial plots is based on code by Philip Mansfield.

  • The exact solution to the Sedov-Taylor explosion problem was adapted from the Gandalf code by Hubber et al. (2018).

  • Big thanks to all the graduate students at the University of Maryland who have experimented with Ulula, particularly Ell Bogat, Emeline Fromont, Giannina Guzman Caloca, and Calvin Osinga!

Version history

Version 0.4.2 (released X/X/2025)

Version 0.4.1 (released 3/5/2025)

  • Added the HLLC Riemann solver and improved tests.

  • Added Gresho vortex setup.

  • Added 1D advection setup.

  • Added the possibility of plotting temperature in Kelvin.

  • True solution not plotted in 1D plots if not provided by setup.

  • Simultaneous 1D and 2D plotting.

  • Added radial and azimuthal velocity to plottable quantities.

Version 0.4.0 (released 2/5/2025)

This is a major release. The most important changes are:

  • Implemented proper 1D simulations.

  • Added plotting of ghost cells in 1D.

  • Added isothermal equation of state.

  • Added user-defined changes at runtime and boundary conditions.

  • Improved setting of simulation parameters.

  • Removed global index variables in favor of adaptable indexing.

  • Added atmosphere and soundwave setups.

Version 0.3.0 (released 1/7/2025)

This is a major release. The most important changes are:

  • Added gravity (fixed acceleration and fixed, user-defined potential).

  • Added wall (reflective) boundary conditions.

  • Added code units and plotting in arbitrary unit systems.

  • Added correct treatment of CFL violations.

  • Added automatic checks on conservation of mass, energy, and momentum (if applicable).

  • Added cloud crushing, free-fall, Rayleigh-Taylor, and tidal disruption setups.

Version 0.2.2 (released 05/20/2021)

Minor changes:

  • Added a check that the final time must be larger when restarting

  • Added to documentation

Version 0.2.1 (released 05/19/2021)

The main runtime interface (see Running Ulula) was reworked significantly:

  • it now accommodates saving and plotting at evenly spaced times rather than snapshots

  • saving, plotting, and movie making can be switched on at the same time

  • the output and plotting times do not interfere with the physical simulation

Version 0.2.0 (released 05/17/2021)

The main features added in this version relate to input/output of files:

  • Added file saving into hdf5 snapshot files

  • Added restarting capability (either manual or in runtime function)

  • Added dictionaries of primitive and conserved fluid quantities for more transparency in the plotting and saving routines

  • Added to documentation

Version 0.1.1 (released 04/02/2021)

This version is mostly a refactoring of the initial checkin, and also contains:

  • Added Sedov-Taylor test case (blastwave explosion)

  • Added radially averaged 1D plots of fluid quantities

Version 0.1.0 (released 03/24/2021)

Initial version. Contains the main hydro solver and examples.