This glossary lists only those variables that are used in vhone.f90 of the beginner's version,
VH-0.5. Variables that are not declared in vhone.f90 are declared in
PPMLR/vh1mods.f90. The 1D arrays listed here are declared a size
(maxsweep), the value of which is nominally set to 1036 in
PPMLR/vh1mods.f90. If you want more than 1024 zones in your grid, you will need
to increase the value of maxsweep.
| Variable name | Variable type | Description |
|---|---|---|
| dt | REAL | time step: time = time + dt for each cycle |
| dt3 | REAL | time step increased by 10%; new time step will not exceed this value |
| dtx | REAL | maximum allowable time step determined by CFL condition |
| dx0 | REAL(:) | array of zone widths; dx0 = dxfac |
| dxfac | REAL | width of every grid zone |
| e | REAL(:) | total energy (internal + kinetic); e(n) is the energy in zone n |
| endtime | REAL | maximum time to run program (not necessarily the ending time) |
| filename | CHARACTER(50) | output file for data at individual time steps |
| gam | REAL | ratio of specific heats |
| gamm | REAL | equal to (gam - 1.0), used to relate pressure to internal energy |
| hstfile | CHARACTER(8) | name of history file |
| i | INTEGER | index for x dimension of multi-D arrays |
| imax | INTEGER | number of physical zones in x dimension (not including ghost zones) |
| n | INTEGER | index for 1-D arrays |
| ncycle | INTEGER | current cycle number of time evolution |
| ncycend | INTEGER | maximum number of cycles to run program (not necessarily the ending cycle) |
| ncycp | INTEGER | number of cycles since last output file was written to disk |
| ndump | INTEGER | not used in VH-0.5 |
| nfile | INTEGER | counter used to name output files; starts at zero and increments for each file written to disk |
| ngeom | INTEGER | flag used to specify geometry of the grid |
| nleft | INTEGER | flag used to specify boundary conditions for left edge of grid |
| nmax | INTEGER | index of last real zone on right side of grid, always = imax+6 (to account for 6 ghost zones) |
| nmin | INTEGER | index of first real zone on left side of grid, always = 7 (to account for 6 ghost zones) |
| nmovie | INTEGER | not used in VH-0.5 |
| nprin | INTEGER | number of cycles executed between writing output files to disk |
| nright | INTEGER | flag used to specify boundary conditions for right edge of grid |
| p | REAL(:) | pressure; p(n) is the pressure in zone n |
| prefix | CHARACTER(len=50) | name used to prefix all output files |
| r | REAL(:) | density; r(n) is the density in zone n |
| ridt | REAL | maximum time to cross a zone at either fluid or sound speed; used to calculate CFL-constrained time step |
| rstrt | CHARACTER(len=2) | restart suffix: call init if = 'no', otherwise restart from dump file |
| svel | REAL | maximum time to cross a zone at sound speed; used to calculate CFL-constrained time step |
| sweep | CHARACTER(len=1) | label for current direction of hydrodynamic update; always = 'x' for 1D hydro in VH-0.5 |
| time | REAL | current simulation time |
| timep | REAL | simulation time since last output file was written to disk |
| tmovie | REAL | not used in VH-0.5 |
| todayis | CHARACTER(len=8) | Today's date as given by call to date_and_time; recorded in history file |
| tprin | REAL | simulation time between successive output files written to disk |
| u | REAL(:) | velocity; u(n) is the velocity in zone n |
| v | REAL(:) | transverse (y) velocity; typically set to zero in 1D hydro |
| w | REAL(:) | transverse (z) velocity; typically set to zero in 1D hydro |
| xa0 | REAL(:) | array of coordinates of the left edge of each zone on the grid |
| xmin | REAL | coordinate of left edge of the grid |
| xmax | REAL | coordinate of right edge of the grid |
| xvel | REAL | maximum time to cross a zone at the fluid speed; used to calculate CFL-constrained time step |