Nek5000 v19.0

What is new?

• Uncoupled multisession (neknek) simulations
• Gather scatter operations across sessions
• Gather scatter options across gtp-planes
• par file support for postnek
• mkSIZE to automatically create SIZE file
• Object and boundary handling
• RANS k-Omega and k-Omega-SST (experimental)
• Online mesh-smoother (experimental)
• ElapsedTime option for writeControl (in par)
• Print runtime-statistics every 500 steps
• Support for GNU > 8.x compilers
• Support for Cray compilers
• Support for ARM compilers
• Add AVM regularization for scalars (experimental)
• FEM_AMG precoditioner (experimental) p40=3
• SEMG_AMG_HYPRE precoditioner (experimental) p40=2
• CHT support for generic fld reader
• Overwrite core routines in usr
• Lagrangian phase model - LPM (experimental)
• Distributed gllnid/gllel (experimental)
• Add parMetis partitioner
• Add parRSB partitioner
• Add CGNS mesh converter
• Support p0th with Helmholtz
• Update to GSLIB v1.0.5 and HYPRE v2.15.1
• Various bug fixes

What you may have to change to be compatible

• Remove PPLIST symbol NEKNEK (not required anymore)
• Use valint instead of ubc in userbc for neknek
• Remove multimesh_create call from usr file (not required anymore)
• Adjust calls to interpolation wrapper according to new interface in interp.f
• Remove common block CTORQ from usr (now part of OBJDATA included in TOTAL)
• Use nekamg_setup tool instead of amg_hypre (required for semg_amg preconditioner)
• Your parameters to the reserved user space param(170) - param(200)
• Set lelr in SIZE for restart using muliple files (check value in file header)
• Use planar_avg() instead of planar_average_z etc.
• Rename AMG input files (example: amg_Aff.dat -> ethier.amgAff.dat)

Known Bugs

643
635
634
628
562
65

Thanks to our Contributors

We are grateful to all who added new features, filed issues or helped resolve them, asked and answered questions, and were part of inspiring discussions.

Nek5000 v17.0

Major Features and Improvements

• New paramater file .par (replacing .rea)
• Added OIFS for moving mesh
• Added Moving mesh for PN/PN
• Improved stability for varying visosity and PN/PN
• Added support for mixed Helmholtz/CVODE solves
• New fast AMG setup tool based on HYPRE
• New EXODUSII mesh converter
• New interface to libxsmm (fast MATMUL library).
• Extended lowMach solver for time varying thermodynamic pressure
• Added DG for scalars
• Added support for implicit none in .usr file
• Reduced solver initilization time (parallel binary reader for re2, ma2 and AMG files)
• Restart from arbitrary fld-file (multiple files not supported) using interpolation
• Optional new user friendly SIZE file format (see SIZE.template)
• Refactored NEKNEK
• Added high-pass filter relaxation (alternative to explicit filter)
• Refactored build system
• Refactored residual projection including support for scalars and coupled Helmholtz solves

Backwards-Incompatible Changes

• Replaced usr interpolation wrapper intpts() by intp() with a different interface
• Replaced g2gi() by new generic fld reader gfldr()
• Moved makenek from core to bin folder
• Removed MOAB support
• Replaced hpts.in/hpts.out by <casename>.his
• Eliminated PPLIST symbol MPIIO as it is enabled by default now (only active if p65=1 or nfiler=1)
• NENEK requires latest SIZE file format
• Eliminated PPLIST symbol AMG_DUMP as we dump the files automatically if they don't exist
• Eliminated PPLIST symbol AMG as it is a runtime parameter now (rea:p40 or par:preconditoner=semg_amg in PRESSURE section)
• Changed various key/values for .par
• Changed meaning of param(26) to be the targetCFL instead of OIFS substeps

Known Bugs

65

Thanks to our Contributors

This release contains contributions from the Nek5000 core developers, as well as:

@ggiannako, @nicooff, @kmittal2, @RonRahaman, @cliosaglietti, @EvelynOtero, @MattiaBr, @maxhutch, @hackljf, @negips, @kento, @nchristensen, @spatel7286

We are also grateful to all who filed issues or helped resolve them, asked and answered questions, and were part of inspiring discussions.