CCAPS_atm_const
This is a version of the Cell Centred Approximate Projection Solver CCAPS for the specific case of a time-independent background state in hydrostatic equilibrium (HSE). It allows for atmospheric compression / expansion effects, and so is not fully incompressible (but is still "sound-proof").
The code has been split into different versions because tracking options for the various classes of model equations and extra physics options was becoming unwieldy. Given the main objectives of SimpleCFD, the extra reproduction of core code is acceptable given the gains in clarity, etc.
ccaps_atm_const solves the equations:
where
The above are obtained from the usual equations by defining a horizontally averaged base state that consists of a "background" density which is in hydro-static equilibrium and subtracting the quantities off, i.e.
and supplementing with additional correction terms for the generalised pseudo incompressible regime described in Vasil+2013 .
Using (more-or-less) the method outlined in Chapter 15 of this book.
For further details (such as how to build, run, setup a problem) see also the main CCAPS wiki.
These tests are built in and can be configured in initial_conditions.f90 and control.f90.
The code can run the same homogeneous density cases (minion and shear) as the main CCAPS code and finds agreement.
Can be run for an RTI and compared to CCAPS_vardens (ADD LINK), which is a variable density / no background state solver. Put figures here.
Can also be compared to CCAPS_vardens. Put figures here.