Chombo 3.2 Release Notes

It has been two years since Chombo 3.1 was released. The major changes are listed below.

You can contact the Chombo development team at [email protected] and the Chombo users e-mail group at [email protected].

• We have implemented interfaces to the PETSc solver library (http://www.mcs.anl.gov/petsc/) which generate matrices for discretizations on AMR hierachies of grids for use in PETSc solvers. This is useful for problems, such as those with geometrically complex material coefficients, in which our native geometric multigrid solvers are not efficient. An accompanying single-level interface is also useful as a bottom-solver for use with our geometric multigrid solvers. Details can be found in Chapter 7 in doc/chomboDesign.pdf.

• Chombo has updated to use the HDF5 1.8 API, although support for the 1.6 API is still in place for this release. This means (among other things) that the -DH5_USE_16_API compiler flag is no longer required.

• Hybrid parallelism is now possible in Chombo, the base classes have been made thread-safe. OpenMP is used in some of the library code including Godunov and Poisson solvers. Among the released examples AMRGodonov and AMRPoisson/exexCell can use OpenMP.
  
  Current status: There are several problems with the OpenMP implementation that are being corrected. In a few weeks, corrections will be merged into the Chombo 3.2 release to make the OpenMP code fully functional.

• Embedded boundary generation has been optimized for run time, memory usage, and parallel load balancing.

• We have added an embedded-boundary (EB) adaptive mesh refinement (AMR) compressible Navier-Stokes code in releasedExamples/EBAMRCNS.

• Also, as one might expect, this release contains many (well, not that many) bugfixes and minor capability upgrades over the 3.1 release.

Chombo 3.1 release notes.