real abux f=E15.8 b=4 n='hydrogen abundance (number fraction)' u=1 & c0='standard solar mixture' 0.90851003E+00It has no practical consequences because the actually used chemical composition is determined by the files for equation of state and opacity.
real abuy f=E15.8 b=4 n='helium abundance (number fraction)' u=1 & c0='standard solar mixture' 0.90850003E-01It has no practical consequences because the actually used chemical composition is determined by the files for equation of state and opacity.
real qmol f=E15.8 b=4 n='mean molecular weight' u=u & c0='standard solar mixture' 0.13018000E+01It has no practical consequences because the actually used chemical composition is determined by the files for equation of state and opacity.
real gamma f=E15.8 b=4 n='Adiabatic coefficient' u=1 & c0='0.0/1.6666666666666/1.4' 0.0It has no practical consequences because the actually used chemical composition is determined by the files for equation of state and opacity.
character gravcorr_terms f=A80 b=80 & n='Type of gravity correction in Roe solver' & c0='off0/default0/default/default2/default3' default5In recent versions this coupling has to be specified at compile time with the switch
rhd_hyd_gravcorr_p01, see Sect. 3.4
real c_test1 f=E15.8 b=4 n='rho_min' u=g/cm^3 1.0E-25
real c_visneu1 f=E15.8 b=4 & n='Linear viscosity parameter (von Neumann-Richtmyer type)' u=1 0.0
real c_visneu2 f=E15.8 b=4 & n='Quadratic viscosity parameter (von Neumann-Richtmyer type)' u=1 0.0
LHDradmodule partly supports periodic boundaries (not complete yet, do not use!). In this version the lower part of the model can be computed in diffusion approximation. The number of points in diffusion approximation can be set with e.g.
integer n_radthickpoint f=I4 b=4 & n='Number of grid points with optically thick (diff.) approximation' & c0='0: no diffusion approximation' 0Setting this value to
0means that the diffusion approximation is not used in any part of the model.
LHDradmodule the opacity along each ray can be smoothed. The amount of smoothing can be set e.g. with
real c_radkappasmooth f=E15.8 b=4 n='Opacity smoothing parameter' u=1 & c0='0.0: no smoothing, 0.25: light smoothing, 0.666: strong smoothing' 0.0The smoothing can perhaps reduce the noise in the intensity images somewhat but has no general beneficial effect and should usually not be used.
LHDradmodule the 3D temperature array can be smoothed. The amount of smoothing can be set e.g. with
real c_radtsmooth f=E15.8 b=4 n='Temperature smoothing parameter' u=1 & c0='0.0: no smoothing, 0.5: reasonable smoothing, 1.0: max. smoothing' 0.0The smoothing can sometimes reduce the noise in the intensity images but causes/amplifies some anomalies of the radiative Greens function: Some cool cell just above the sharp sub-photospheric temperature drop are not heated but cool further down. Negative temperature spikes may result. This smoothing should not be used anymore.
LHDradmodule there exists a simple prescription for the radiative pressure (reasonable in the optically thin) which can be activated with
character radpressure f=A80 b=80 n='Radiation pressure mode' & c0='on/off' onAllowed values are
on: Radiation pressure on.
off: Radiation pressure off.
LHDradmodule: The fraction the interpolated temperature (at a point on the ray) may exceed the minimum temperature at its four neighbors on the HD grid can be set e.g. with
real c_radtintminfac f=E15.8 b=4 & n='Temperature interpolation parameter' u=1 & c0='<1.0: only bilinear, 1.1: reasonable weighting between min. und bil.' 0.0The introduction of this parameter was an attempt to reduce the negative (cooling) effect of a single hot cell on its cool neighbors. It should be switched off e.g. by setting it to
integer dtimestep_out_fine f=I4 b=4 n='Output time step number' u=1 & c0='dtimestep_out_fine<0 => no output' -1
character outfile_fine f=A80 b=80 n='Output file name' rhd.fineLeaving it empty means that no file of this type is written. Specifying it means the same (yet).
character outform_fine f=A80 b=80 n='Output file format' & c0='formatted/unformatted' unformattedAllowed values are
unformatted: (default) fast compact (possibly machine-dependent) output: strongly recommended
formatted: slow (machine-independent) output, big files
character outconv_fine f=A80 b=80 n='Output file conversion' & c0='ieee_4/ieee_8/crayxmp_8/native' ieee_4The allowed values depend on the machine. Leaving this field empty means that the default is chosen that is build into the local UIO module. If the type
ieee_4is supported (which is always the case, so far) it should be chosen. This parameter can be specified but there is no corresponding output file in COBOLD yet.