Calling wells()->number_of_wells on nullptr causes segmentation fault. This
occurs when running a deck without wells. Allowing WellsManager::init to
continue for decks without wells enables the well struct to be set.
Authored by Sveinung Rundhovde & Lars Petter Hauge
simulator
1) Don't depend on legacy code for communicating the data::wells
2) Bugfix. Store globalIdx instead localIdx in data::wells::complitions
3) Move ThreadHandle to ebos
Currently we run into issues with the parallel AMG if
redistribution happened on the coarsest level. That is
not detected by AMG and it will construct smoothers on
all processors present before the redistribution. Some of
them will get OwnerOverlapCommunication objects that have
an invalid MPI communicator in them (MPI_COMM_NULL) and an
MPI_ERROR will be raised as we communicate in the constructor.
With this patch we detect this situaton and set the pointer to
OwnerOverlapCommunication to null to prevent communication. A
sanity check that the matrix has zero rows has been added.
Often it is claimed by CPR-AMG evangelists that this will make the pressure
system more elliptic. That may be the case. But even more important it also
decouples the pressure from the saturations.
Without this approach the pressure correction influences the smoothing of the
full system too much and e.g. for Norne CPR is worse than simple block ILU0.
This seems to have been forgotten previously. Now the code int CPRPreconditioner.hpp
uses ParallelOverlappingILU0 instead of SeqILU[0n]/BlockPreconditioner which
makes the code more slim.
The approach is inspired by Geiger's system-amg but we use dune-istl
aggregation AMG for it. On the fine level all unknowns attached to a cell
form a matrix block and are treated fully coupled. To form the first
coarse level system we use only the pressure component to guide the aggregation
and neglect all other unknowns on the fine level. All other level are formed
in the usual way by scalar aggregation.
Currently,it has to be requested for flow_ebos manually by passing
"linear_solver_use_amg=true amg_blackoil_system=true" to it.
these files take the longest to compile. moving them to the beginning
speeds things up forn parallel builds because the remaining compile
can be compiled while dealing with the flow_ebos files while the build
stalls if these files are at the bottom of the list because they are
required for the library.
