further, this cleans up the code of the parameter system and the
startup routines a bit and finally, it adds positional parameters
support to ebos as well as brief descriptions to ebos and the lens
problem.
IMO the term "vanguard" expresses better what these classes are
supposed to do: level the ground for the cavalry. Normally this simply
means to create and distribute a grid object, but it can become quite
a bit more complicated, as exemplified by the vanguard classes of
ebos..
instead of passing a "minimal" fluid state that defines the
thermodynamic conditions on the domain boundary and the models
calculating everything they need based on this, it is now assumed that
all quantities needed by the code that computes the boundary fluxes
are defined. This simplifies the boundary flux computation code, it
allows to get rid of the `paramCache` argument for these methods and
to potentially speed things up because quantities do not get
re-calculated unconditionally.
on the flipside, this requires slightly more effort to define the
conditions at the boundary on the problem level and it makes it less
obvious which quantities are actually used. That said, one now has the
freedom to shoot oneself into the foot more easily when specifying
boundary conditions and also tools like valgrind or ASAN will normally
complain about undefined quantities if this happens.
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.)
i.e., the solvers.hh file is removed. The main reason for this is that
it avoids having to distribute a file with a potentially incompatible
license (i.e., GPLv2 + template exception vs GPLv2+), but the
home-brewn bicgstab solver also seems to perform a tiny bit better.
