This commit adds support for assigning the initial phase pressure
distribution to a subset of the total grid cells. This is needed in
order to fully support equilibration regions. The existing region
support (template parameter 'Region' in function 'phasePressures()')
was only used/needed to define PVT property (specifically, the fluid
phase density) calculator pertaining to a particular equilibration
region.
This commit adds a simple facility for calculating initial phase
pressures assuming stationary conditions, a known reference pressure
in the oil zone as well as the depth and capillary pressures at the
water-oil and gas-oil contacts.
Function 'Opm::equil::phasePressures()' uses a simple ODE/IVP-based
approach, solved using the traditional RK4 method with constant step
sizes, to derive the required pressure values. Specifically, we
solve the ODE
dp/dz = rho(z,p) * g
with 'z' represening depth, 'p' being a phase pressure and 'rho' the
associate phase density. Finally, 'g' is the acceleration of
gravity. We assume that we can calculate phase densities, e.g.,
from table look-up. This assumption holds in the case of an ECLIPSE
input deck.
Using RK4 with constant step sizes is a limitation of this
implementation. This, basically, assumes that the phase densities
varies only smoothly with depth and pressure (at reservoir
conditions).
this has recently been moved there. Since redundancy is considered to
be bad, switch eWoms to it.
I've tested this with Norne: No measureable difference, as expected.
for some reason the results have changed. (IMO, the new ones look more
correct in paraview.) The reason this was not discovered earlier is
that this test depends on the presence of dune-alugrid and the CI
infrastructure does not deal with this.
the reason is that cmake cannot file(COPY) them. this is probably due
to constraints of a crappy operating system that is made by a
microscopical and tender company which is based close to Seattle.
there seems to be only a *very* limited amount of interest, the code
of the model is quite complex and there are currently no suitable
discretizations for free-flow equations in eWoms (i.e., the model
tends to be very unstable and oscillates a lot). Combined, all of this
makes maintaining this model a pain in the back, so let's remove it
some interest in these kinds of problems surfaces and until
appropriate discretizations -- like staggered grid methods -- are
available.
This works by having a "focus degree of freedom" during
linearization. When evaluating the local residual, all derivatives of
the residual/fluxes are with regard to the primary variables of that
DOF.
The two main offenders were the Forchheimer velocity model and the
model for the Stokes equations. To ensure that they continue to work,
the "powerinjection" and the "stokestest2c" problems are now both
compiled and tested with both, automatic differentiation and finite
differences, and the results of these tests is compared against the
same reference solution.
The majority of the time required to develop this patch was actually
required for testing: All tests compile and pass with debugging and
aggressive optimization flags with at least GCC 5, GCC 7 and clang
3.8, as well as Dune 2.3 and 2.4. Also, the results of flow_ebos stay
identical for Norne whilst the performance difference is below the
measurement noise on my machine. (the version with this patch applied
was actually about 1% faster.)
this belongs to the `tests/data` directory, not into the toplevel
`data` directory. Also, the input ART file for this has been renamed
to `fracture-raw.art` to avoid race conditions.
for the vertex-centered finite volume discretization, the relevant
position for calculating the gradient is *not* the position of the
center of the *sub*-control volume, but the center of the whole
control volume.
Since this patch changes the gradients of all VCFV simulations that
use twopoint gradients, quite a few new reference solutions are
required by this PR. I've looked at all of them manually and made sure
that they look reasonable. (The PR also includes a new reference
solution for the test for the adaptive finger problem -- which uses
ECFV -- but that's because the grid refinement seems to be quite
sensitive to the solution proceedure for that problem, not because
there's any difference in the solutions that can be noticed visually.)
note that all simulations that use element centered finite volume
discretization because there sub-control volumes are identical to full
control volumes. In particular, ebos -- and by extension `flow_ebos`
-- is unaffected because it does not even use that code.
i.e., using clang 3.8 to compile the test suite with the following
flags:
```
-Weverything
-Wno-documentation
-Wno-documentation-unknown-command
-Wno-c++98-compat
-Wno-c++98-compat-pedantic
-Wno-undef
-Wno-padded
-Wno-global-constructors
-Wno-exit-time-destructors
-Wno-weak-vtables
-Wno-float-equal
```
should not produce any warnings anymore. In my opinion the only flag
which would produce beneficial warnings is -Wdocumentation. This has
not been fixed in this patch because writing documentation is left for
another day (or, more likely, year).
note that this patch consists of a heavy dose of the OPM_UNUSED macro
and plenty of static_casts (to fix signedness issues). Fixing the
singedness issues were quite a nightmare and the fact that the Dune
API is quite inconsistent in that regard was not exactly helpful. :/
Finally this patch includes quite a few formatting changes (e.g., all
occurences of 'T &t' should be changed to `T& t`) and some fixes for
minor issues which I've found during the excercise.
I've made sure that all unit tests the test suite still pass
successfully and I've made sure that flow_ebos still works for Norne
and that it did not regress w.r.t. performance.
(Note that this patch does not fix compiler warnings triggered `ebos`
and `flow_ebos` but only those caused by the basic infrastructure or
the unit tests.)
v2: fix the warnings that occur if the dune-localfunctions module is
not available. thanks to [at]atgeirr for testing.
v3: fix dune 2.3 build issue
for some reason, there are differences between my laptop with
optimizations and my workstation in debug mode. since the results look
_very_ similar in paraview, let's treat them both as equally valid.
as a side effect, two-point gradients are now used by default for the
vertex-centered finite volume discretization. (because P1-FE gradients
require the FE shape functions and those are provided by
dune-localfunctions.)
as a consequence, this triggered an update of quite a few reference
solutions: the differences are measurable, but as far as I can see,
the results are compareable. also, this commit regresses the
performance of the test for the reservoir problem with the vertex
centered finite volume scheme a bit. While I would not bet a house on
the reason, I'm pretty sure that this is caused by the switch from P1
FE gradients to two-point ones.
Note that even though I'm the author of this patch, it shamelessly
rips off substantial parts of the @dr-robertk's patch:
https://github.com/OPM/ewoms/pull/69
this problem did not work properly anyway: it oscillated like hell
(very likely to the spatial discretization used being inappropriate)
and it did not even converge if more than a single iteration was
required.
i.e., in most cases the initial solution will be written into file
$SIM_NAME-00000.vtu and each time step will be written to the file
with the same number as the one printed during the simulation. (note
that this statement does not apply if the visualization files are not
written for all time steps.)
now, the dune-alugrid module is required if these tests are to be
run. (note that due to the fact that the OPM build system has not been
detecting the legacy alugrid library for a while, the practical
implications of this patch should be small to non-existant.)
the in-file lists of authors has been removed in favor of a global
list of authors in the LICENSE file. this is done because (a)
maintaining a list of authors at the beginning of a file is a major
pain in the a**, (b) the list of authors was not accurate in about 85%
of all cases where more than one person was involved and (c) this list
is not legally binding in any way (the copyright is at the person who
authored a given change, if these lists had any legal relevance, one
could "aquire" the copyright of the module by forking it and removing
the lists...)
the only exception of this is the eWoms fork of dune-istl's solvers.hh
file. This is beneficial because the authors of that file do not
appear in the global list. Further, carrying the fork of that file is
required because we would like to use a reasonable convergence
criterion for the linear solver. (the solvers from dune-istl do
neither support user-defined convergence criteria not do the
developers want support for it. (my patch was rejected a few years
ago.))
this has slowly become a hassle to support (i.e., it cluttered the
source with many #if's and in particularly the code was not tested
with Dune 2.2 on a regular basis). Also, Dune 2.3 has been out since
more than two years, so IMO it is not asked too much to ask people who
want to use the latest and greatest version of ewoms to upgrade their
Dune.
the changes enable the storage cache and the intensive quantity cache
for all simulators of the lens problem and automatic differentiation
for the one which uses the ECFV discretization.
while the performance improvements are not worthwhile for the problem
in its default incarnation (using automatic diffentiation even
slightly degrades performance), it speeds up linearization by about
30% if the grid exhibits 16 times as many elements (e.g. by passing
the --grid-global-refinements=2) parameter.
dune-alugrid >= 2.4 changed the element ordering changed from
lexicographical ordering to one defined by a space filling curve. the
old reference solutions are still valid (and obtained if older
versions of dune-alugrid are used) and are thus retained.
