[FLASH-USERS] FLASH4.2 released

seyit at astro.rug.nl seyit at astro.rug.nl
Sat Feb 8 16:37:08 EST 2014


Dear Developers (Devs),

Congratulations with this release and Thanks! As a long time user, I have
to admit, I cannot keep up with the releases. I'm still with 4-beta.
However, you guys, and everybody that contributes, provide a tremendous
work that benefits the whole community and helps advancing science!

Kind regards,
Seyit




> Dear Users,
>
>  The Flash Center is pleased to announce the release of the new version of
> the FLASH code, version 4.2.
>
> Best,
> -- the Flash Center Code Group
>
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> !!!!!  New in FLASH 4.2  (since the FLASH 4.0.1 patch)   !!!!!
> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
>
> Added CCSN physics from Sean Couch:
> * Complete nuclear EOS routines (physics/Eos/EosMain/Nuclear)
> * Local neutrino heating/cooling
> (physics/sourceTerms/Heat/HeatMain/Neutrino)
> * Multispecies neutrino leakage
> (physics/RadTrans/RadTransMain/NeutrinoLeakage)
> * And if he gets around to it:  Multidimensional Core-Collapse supernova
> test problem
>   (source/Simulation/SimulationMain/CCSN)
>
> Added from Dean Townsley (not previously included, or previously not
> existing):
> * physics/sourceTerms/Flame unit
> * physics/sourceTerms/Turb unit
>
> * Updates to Barnes Hut tree gravity solver contributed by Richard Wunsch,
>   developed in collaboration with Frantisek Dinnbier (responsible for
> periodic
>   and mixed boundary conditions) and Stefanie Walch.
>
> Contributed from Christoph Federrath:
> * Significant updates for Sink Particles
> * New 'FromFile' implementation of Stir unit, now sitting beside the older
>   'Generate' implementation
>
> Two new optimizations of the unsplit solvers, Hydro_Unsplit and
> MHD_StaggeredMesh,
> in source/physics/Hydro/HydroMain/unsplit. These new optimized unsplit
> solvers
> are the default implementations of the unsplit hydrodynamics and MHD
> solvers
> in FLASH 4.2. The old version of the unsplit solvers are now found in
> source/phycis/Hydro/HydroMain/unsplit_old.
>
> Capabilities for 3T magnetohydrodynamics, for the first time.
>
> New magnetic resistivity implementation, Spitzer HighZ, for HEDP problems.
> Extended support for resistivity in cylindrical geometry in the unsplit
> solver.
>
> Laser - Async communication (experimental), some reorganization.
> New feature - can run EnergyDeposition once every n time steps.
>
> Updates to HYPRE solver coupling - avoid communicator leak with 2.0.9b.
> Some changes in MGD code for increased correctness.
>
> Threading for unsplit MHD is now available. Both strategies are supported
> by the new code.
>
> New, improved multipole Poisson solver, implementing the algorithmic
> refinements described in Couch, S.M., Graziani, C., and Flocke, N., ApJ
> 778,
> 181 (2013), http://dx.doi.org/10.1088/0004-637X/778/2/181,
> http://arxiv.org/abs/1307.3135.  Specifically:
> * Potential calculated at cell faces and averaged to produce cell-centered
>   values, rather than directly at cell centers, so as to eliminate a
> convergence
>   failure due to cell self-gravity
> * Expansion center located at "square-density-weighted center-of-mass", to
>   minimize angular power at high multipoles
>
>
> (some smaller changes:)
> * The code includes stubs for several additional code units for which
>   we do not include implementations in this release (TreeCol, NSE,
>   SolidMechanics, IncompNS, ImBound). Implementations may be available
>   separately from their authors, and / or may be included in a future
>   FLASH release.
> * Hydro codes avoid unnecessary Eos calls on guard cells, this uses
> skipSrl
>   flag to Eos_guardCells routine.
> * New Grid_bcApplyToRegionMixedGds API allows users to implement boundary
>   conditions that take several types of solution variables (CENTER, FACE)
>   into account.
>
>
>
> Caveats, Limitations
> --------------------
>
> Simulations results obtained with this version of FLASH should not be
> expected to match exactly with results from previous versions.
> Differences can be due to algorithmic changes in solvers, in particular
> the unsplit Hydro and MHD implementations. Results from simulations that
> use the HYPRE library for Diffusion and/or RadTrans operators may be
> slightly different because we invoke HYPRE with slightly different
> parameters (based on suggestions from HYPRE authors).
> Another source of unexpected differences is a change in how we compute
> block boundary coordinates when an AMR Grid starts with more than one
> root block (i.e. any of NBlockX,NBlockY,NBlockZ > 1), leading to
> a difference in rounding errors under some scenarios.
>
> Several code units have provisions for being threaded (OpenMP directives),
> but these have not been recently tested and may require some adaptation.
>
>
>
> The release is available at:
>
> http://flash.uchicago.edu/site/flashcode/
>
>
>
> Many, but not all parts of FLASH4 are backwards-compatible with
> FLASH2. There are no architectural changes from FLASH3 to FLASH4. The
> Flash code group has written extensive documentation
> detailing how to make the transition from FLASH2 to FLASH3 as smooth
> as possible.  The user should look to:
>
> http://flash.uchicago.edu/site/flashcode/user_support/
>
> The website also contains other documentation including
> a User's Guide and a developer's section.  A new feature in FLASH3
> documentation is the online description of the public interface
> routines to various code units.
>
>
> FLASH should be portable to most UNIX-like operating systems with a
> python interpreter, Fortran 90 compiler,  C compiler, and MPI library.
>
>
>
> Development of the FLASH Code was funded by the DOE-supported
> ASC/Alliance Center for Astrophysical Thermonuclear Flashes,
> and continues to be funded by DOE NNSA and NSF.  We
> acknowledge support received from Lawrence Livermore National
> Laboratory and the University of Chicago.
>
> All publications resulting from the use of the FLASH Code must
> acknowledge the Flash Center for Computational Science.
>   Addition of the following text to the paper acknowledgments
> will be sufficient.
>
>          "The software used in this work was in part developed by the
>          DOE-supported Flash Center for Computational Science
>          at the University of Chicago."
>
>





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