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).
Notation implies that we are going to be given symbols which
represents values or such (which arguably could be true since the
path is a particular value, and from programming we are used to
multi-letter symbols perhaps also with whitespace, but it's a
stretch), but Terminology is more accurate, as this section
describes fits the definition better: it is a vocabulary of
technical terms.
Hat tip: @bska
Give a brief description of each of the modules that comprises the build
system, and the suffices that is used to form a virtual structure of
variables for each project.
on CLang 3.4 svn this produced
```
/home/erne/src/opm-core/opm/core/pressure/fsh.h:20:9: warning: 'OPM_FSH_HEADER_INCLUDED' is used as a
header guard here, followed by #define of a different macro [-Wheader-guard]
```
which is correct...
this simplifies the template meta programming a bit. (Which does not
mean that it suddenly gets easy.) The main motivation for this work is
to make the splices feature work properly which allows eWoms to
properly select the spatial discretization at any point.
Further, the number of type tags a node can inherit from now is truely
unlimited thanks the the generic tuple reversal class provided by
https://sydius.me/2011/07/reverse-tuple-in-c/ . (before, the maximum
number of nodes from which a type tag could inherit was 11, so this
limitation did not really matter in practice.)
