Averaged quantities (timevar)

A text file containing several averaged quantities in a column style file. The variables to be written are choosen in snoopy.cfg (see output.timevar_vars). The following strings can be used in timevar_vars:

t: time of the simulation
ev: Box averaged kinetic energy (incompressible)
vxmax: x velocity maximum
vxmin: x velocity minimum
vymax: y velocity maximum
vymin: y velocity minimum
vzmax: z velocity maximum
vzmin: z velocity minimum
vxvy: xy component of the (incompressible) Reynolds stress (box averaged)
hv: kinetic helicity
w2: total enstrophy

when MHD is on, the following quantities can also be computed:

em: Box averaged magnetic energy
bxmax: x magnetic field maximum
bxmin: x magnetic field minimum
bymax: y magnetic field maximum
bymin: y magnetic field minimum
bzmax: z magnetic field maximum
bzmin: z magnetic field minimum
bxby: xy component of the Maxwell stress
hc: box averaged cross helicity
hm: box averaged magnetic helicity
j2: box averaged current square
az2: box average vertical component of the vector potential squared (conserved in 2D)
vxaz: correlation tensor vx*az

when BOUSSINESQ is on, the following quantities can also be computed:

et: Box averaged thermal energy
thmax: potential temperature maximum
thmin: potential temperature minimum
thvx: correlation th*vx (turbulent transport of heat in x)
thvz: correlation th*vz (turbulent transport of heat in z)

when COMPRESSIBLE is on, the following quantities can also be computed:

dmax: maximum of the density field
dmin: minimum of the density field
dvxvy: xy component of the (compressible) reynolds stress

The average time between two lines in the timevar file is set by output.timevar_step (snoopy.cfg). This file can be read using a Matlab script provided in the Snoopy distribution (see Timevol script)

Shell integrated spectra (spectrum.dat)

This text file contains shell integrated spectra computed on-the-fly by the code. It includes kinetic and magnetic spectra plus transfer spectra relevant to MHD turbulence. For a complete description, see output.c. These files can be read using a Matlab script provided in the Snoopy distribution (see ReadSpectrum script)

The average time between two outputs in spectrum.dat is set by output.timevar_step (snoopy.cfg)

NOTA: the spectrum output routines are still in developement.

Snapshots

Snapshots can be written in vtk legacy format (.vtk) in the data directory. VTK files can are read natively by Paraview 2-3 or Visit, available for free on the web. Several Matlab script are also provided in the Snoopy distribution to read VTK files (see Get_frame script). The fields written in the VTK files are by default vx,vy and vz plus bx,by,bz when MHD is on, th (potential temperature) when BOUSSINESQ is on and wx,wy,wz (vorticity) when output.vorticity is true (see snoopy.cfg).

The average time between two snapshot outputs is set by output.snapshot_step (snoopy.cfg)

Restart dump files

Binary restart file. A maximum of two restart dumps can be found in the running directory: dump.dmp and dump_sav.dmp. The former is the more recent dump whereas the latter is the preceeding dump. Older dumps are deleted during the execution. It is possible to restart the code from a restart dump setting the restart option in snoopy.cfg to true. See output.c for a complete description.

The average time between two dump file outputs is set by output.dump_step (snoopy.cfg)