# GfsTime

(Difference between revisions)
 Revision as of 05:35, 23 April 2008GeordieMcBain (Talk | contribs) (new page, copied from tutorial)← Previous diff Revision as of 05:39, 23 April 2008GeordieMcBain (Talk | contribs) (linked to rt.html for example of dtmax)Next diff → Line 5: Line 5: where i is the time step number and t is the physical time. The end identifier specifies that the simulation should stop when the physical time reaches the given value. It is also possible to stop the simulation when a specified number of time steps is reached, using the iend identifier. If both end and iend are specified, the simulation stops when either of these are reached. By default, both end and iend values are infinite. where i is the time step number and t is the physical time. The end identifier specifies that the simulation should stop when the physical time reaches the given value. It is also possible to stop the simulation when a specified number of time steps is reached, using the iend identifier. If both end and iend are specified, the simulation stops when either of these are reached. By default, both end and iend values are infinite. - Another parameter, dtmax, can be used to cap the time-step. + Another parameter, dtmax, can be used to cap the time-step, as in the [http://gfs.sourceforge.net/examples/examples/rt.html#htoc5 Rayleigh–Taylor] example + + Time { end = 1 dtmax = 5e-3 }

## Revision as of 05:39, 23 April 2008

GfsTime defines the physical and the computational time. By “computational time” I mean the number of time steps performed. By default both the physical time and the time step number are zero when the program starts. It is possible to set different values using for example

``` GfsTime { t = 1.4 i = 32 end = 0 }
```

where i is the time step number and t is the physical time. The end identifier specifies that the simulation should stop when the physical time reaches the given value. It is also possible to stop the simulation when a specified number of time steps is reached, using the iend identifier. If both end and iend are specified, the simulation stops when either of these are reached. By default, both end and iend values are infinite.

Another parameter, dtmax, can be used to cap the time-step, as in the Rayleigh–Taylor example

``` Time { end = 1 dtmax = 5e-3 }
```