[FLASH-USERS] FLASH4-beta released

[dongwook at flash.uchicago.edu]

Dear James again,

There was a mistake on what I said in my earlier email:

> (2) n+1 update of gravity as a source term (improvement):
> What we had before was to add gravity components to momenta first and then
> energy. However, after carefully testing a set of numerical problems and
> comparing the unsplit solver's results with those of the split PPM solver,
> we found that the ordering should be changed. We now have energy update
> first followed by momenta update.

Correction to the above paragraph:

* Old way: energy update first followed by momenta update
* New way: momenta update first followed by energy update USING the
updated momenta

This new way is also the same logic/order as the one done in the split PPM
solver.

Sorry for the confusion.

Best,
Dongwook


>
>> Hi Klaus, I was unable to find any additional information in the user
>> guide
>> on this point in the release notes:
>>
>> The use of Gravitational acceleration is handled more accurately in
>>> Hydrodynamics.
>>
>>
>> Could you clarify as to what the improvements are?
>>
>> Thanks!
>> - James
>>
>> On Wed, Feb 1, 2012 at 11:33 AM, Klaus Weide
>> <klaus at flash.uchicago.edu>wrote:
>>
>>>
>>> The Flash Center is pleased to announce the beta release of the next
>>> version of the FLASH code, version 4 beta. FLASH 4 beta includes
>>> several new capabilities and resolves many bugs found in
>>> previous releases up to 4-alpha.
>>>
>>>
>>> The capabilities added since the alpha release are :
>>>
>>> Capabilities added since the FLASH4-alpha include:
>>>
>>> * 3T capabilities, support for non-Cartesian geometry, and support for
>>> stationary rigid bodies in the unsplit hydrodynamics solver
>>>
>>> * Upwind biased constrained transport (CT) scheme in the unsplit
>>> staggered
>>> mesh MHD solver
>>>
>>> * Full corner transport upwind (CTU) algorithm in the unsplit hydro/MHD
>>> solver
>>>
>>> * Multi-Temperature Multi-Material Multi-Table Eos
>>>
>>> * Ability to use cold opacities
>>>
>>> * Several solvers have been threaded with two different degrees of
>>> parallelism. The
>>>  block level threading  is coarser grained with one FLASH block being
>>> given to one
>>>  thread, there is a finer grain threading which threads performance
>>> critical loops.
>>>  Both modes use OpenMP.
>>>
>>> * Laser drive is reconfigured and threaded.
>>>
>>> * Several new HEDP simulation setups have been added.
>>>
>>>
>>> Improvements to capabilities since the alpha release include:
>>>
>>> * The HEDP capabilities have been more extensively tested, and are
>>> therefore more robust.
>>>
>>> * Eos related runtime parameters are clearer.
>>>
>>> * Several new shortcuts have been added to make it easier to use the
>>>  new HEDP capabilities.
>>>
>>> * The use of Gravitational acceleration is handled more accurately in
>>> Hydrodynamics.
>>>
>>> * The interface with Hypre is more robust for diffusion.
>>>
>>> * More boundary conditions in PFFT, some Poisson solvers can now handle
>>>  combinations of different boundary conditions (DIRICHLET, NEUMANN,
>>> PERIODIC)
>>>  on different domian boundaries.
>>>
>>>
>>> Known Limitations:
>>>
>>> * The new multipole solver is missing the ability to treat
>>>  a non-zero minimal radius for spherical geometries, and the
>>>  ability to specify a point mass contribution to the potential.
>>>
>>> * Unsplit diffusion does not work in 3D.
>>>
>>> * HYPRE needs to be installed to use Unsplit Diffusion, Unsplit
>>> diffusion
>>>  uses hypre-2.7.0b (might not be backward compatible).
>>>
>>> * Usage of HYPRE Split solver in FLASH4 is only for internal debugging
>>> purposes
>>>  and is not generally recommended for usage.
>>>
>>> * Split diffusion has not been tested with PARAMESH.
>>>
>>> * Some configurations of hydrodynamic test problems with Chombo grid
>>>  show worse than expected mass and total energy conservation.  Please
>>>  see the Chombo section in Hydro chapter of the FLASH user guide for
>>>  details.
>>>
>>> * We have experienced the following abort when running
>>>  IsentropicVortex problem with Chombo Grid:
>>>  "MayDay: TreeIntVectSet.cpp:1995: Assertion `bxNumPts != 0' failed.
>>> !!!"
>>>  We are currently in contact with the Chombo team to resolve this
>>>  issue.
>>>
>>> * The absoft compiler produces erroneous results with optimization in
>>>  gr_markRefineDerefine routine. The results are fine without
>>>  optimization. There may be other files with similar behavior, but
>>>  this is the only one we are aware of.
>>>
>>> * The PG compiler fails to compile source files which contain OpenMP
>>>  parallel regions that reference threadprivate data.  This happens in
>>>  the threaded versions of the Multipole solver and the within block
>>>  threaded version of split hydro.  A workaround is to remove
>>>  "default(none)" from the OpenMP parallel region.
>>>
>>> * The unsplit hydro solver has an issue with preserving symmetry in
>>>  non-fixed block size mode in UG.
>>>
>>> * The ReineckeMeyer setup will not compile with the NAG compiler
>>> because
>>>  of the presence of f77 like file used computing analytical solution
>>>
>>> * We have been unable to use Hyper with OpenMPI in the FLASH code, the
>>>  runs result in execution failures.
>>>
>>> * The -index-reorder setup flag does not work in all the
>>> configurations.
>>>  If you wish to use it please contact the FLASH team.
>>>
>>> * A longer list of changes is contained in the User's Guide in Section
>>> 1,
>>>  What's New in This Release.
>>>
>>> The release is available at:
>>>
>>> http://flash.uchicago.edu/site/flashcode/
>>>
>>> A stripped down version of FLASH3 that may be downloaded without a
>>> license is also available at the same site.  This is essentially the
>>> FLASH framework without any implementations. Additionally a collection
>>> of mini-apps that represent the FLASH workload in many different
>>> configurations is also availble under the general FLASH license
>>> agreement.
>>>
>>>
>>> The Flash Center continues to provide support for "add-ons" to the
>>> code.
>>>
>>> Additionally, the FLASH testing software FlashTest, which became
>>> available with the FLASH3, continues to be available for
>>> download at:
>>>
>>> http://flash.uchicago.edu/site/flashcode/
>>>
>>> The code architecture and most interfaces of FLASH4 are compatible
>>> with FLASH3.  Many, but not all parts are also backward compatible
>>> with FLASH2.  The Flash Center 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 from FLASH3 onward is the
>>> online description of the public interface routines to various code
>>> units. A new feature from the current release is a list of available
>>> setup shortcuts.
>>>
>>>
>>> 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."
>>>
>>
>>
>>
>> --
>> James Guillochon
>> Department of Astronomy & Astrophysics
>> University of California, Santa Cruz
>> jfg at ucolick.org
>>
>