Generate PIG EoS table¶

To generate a customized table for a partially-ionized-gas (PIG) EoS, you must first specify the following options through OPTS += ... entries in the Makefile in miscellaneous/generate_pig_table:

Option	Meaning
`Nrho=240`	Number of intervals (i.e., nodes-1) in the temperature axis of the table
`NT=160`	Number of intervals (i.e., nodes-1) in the density axis of the table
`log10_T_min=1.0_rp`	Minumum log10 of the tabulated temperature / K
`log10_T_max=8.0_rp`	Maximum log10 of the tabulated temperature / K
`log10_rho_min=-20.0_rp`	Minumum log10 of the tabulated density / (g cm^-3)
`log10_rho_max=0.0_rp`	Maximum log10 of the tabulated density / (g cm^-3)
`thr_ne=1.0e-15_rp`	Tolerance threshold of the Secant solver that finds the root of $\sum_i \sum_j(Z_{ij} n_{ij}(n_e))-n_e = 0$
`eps_eta=1.0e-3_rp`	Relative perturbation in a quantity “q” needed to compute its first or second derivative using a 4th-order accurate discretization method on a 5-point stencil
`ddx1=12`	Number of briquettes in the density axis used for MPI parallelization
`ddx2=8`	Number of briquettes in the temperature axis used for MPI parallelization
`USE_QUAD_PRECISION`	To enable 128-bit precision (recommended), otherwise use `USE_DOUBLE_PRECISION`
`USE_H2`	If enabled, adds h2 to the mixture

The provided Makefile will use mpifort to compile the source code, but you can explicitly set the fortran compiler at FC = mpifort.

The mass fractional abundances of a finite list of elements must be provided in generate_pig_table.F90 as

mgrid%X(i_h1) = 0.72_rp
mgrid%X(i_he4) = 0.25_rp
mgrid%X(i_c12) = 0.01_rp
mgrid%X(i_n14) = 0.01_rp
mgrid%X(i_o16) = 0.01_rp

You can then build the executable as

make clean
make

The executable is then ready to be run, using, e.g.,

mpirun -n 96 ./run.generate_pig_table

or by submitting a job script (see miscellaneous/generate_pig_table/pig_table.job).

Note: the number of MPI tasks used to run the executable must match the product of ddx1 and ddx2.

The resulting table has resolution (Nrho+1)x(NT+1) and can be found in miscellaneous/generate_pig_table/pig_table.dat.

In a Phlegethon application, the table path, resolution, and range must be specified in the Makefile of the application by defining the following parameters (here the generated table has been moved to $(DATA))

OPTS += path_to_pig_table=\"$(DATA)/pig_table.dat\"
OPTS += pig_nT_make=161
OPTS += pig_nrho_make=241
OPTS += pig_ltlo_make=3.0_rp
OPTS += pig_lthi_make=8.0_rp
OPTS += pig_ldlo_make=-20.0_rp
OPTS += pig_ldhi_make=0.0_rp

The new table can also be used in Python for postprocessing. To this end, the customized table must be copied to $(DATA).

At this point, when loading a grid snapshot using the functionalities of phloutput, you must specify the name of the new table, e.g.,

sl = h5grid(-1,pig_table='pig_table.dat',NRHO=<NRHO>,NT=<NT>,LOGRHOMIN=<LOGRHOMIN>,LOGRHOMAX=<LOGRHOMAX>,LOGTMIN=<LOGTMIN>,LOGTMAX=<LOGTMAX>)

Note: the call to h5grid will automatically set eos_mode = ['radiation','pig'], so that the ultimate EoS will include the selected mixture of partially ionized species and thermal radiation.