FDS 6.7.7 Maintenance Release

[Kevin]

A new release of FDS has been posted

https://pages.nist.gov/fds-smv/downloads.html

The release notes are posted here

https://github.com/firemodels/fds/wiki/FDS-Release-Notes

Something to note is that this is the last release that includes the FDS+Evac evacuation model built into the FDS source code. It was decided to separate the fire and evacuation models because it is becoming too difficult to maintain both within the same code base. This is especially true because we are transitioning from the traditional FDS "Lego-block" geometry to a new "immersed boundary" geometry where the obstructions no longer have to conform to the underlying rectilinear grid. This transition has been more difficult than we first envisioned, and supporting the Evac routines along with the new immersed boundary routines has proved to be unworkable. 

The future of FDS+Evac is a bit uncertain. Timo Korhonen of VTT, Finland, has been more or less its sole developer over the past 15 years. A few volunteers have stepped up to help, but it is a daunting task to learn both the FDS and Evac source code routines. Those of us who work on the fire routines are not familiar with the Evac routines, so when there is a problem, we cannot step in and help. We anticipate that this situation would only worsen in the years to come, as FDS+Evac is no longer Timo's primary research interest. Nevertheless, Timo is going to try to maintain FDS+Evac as a stand-alone tool, running separately from FDS. We are in touch with Timo and the Pathfinder developers at Thunderhead Engineering (the makers of PyroSim) to ensure that FDS outputs whatever information that an evacuation model would need, in particular, the spatially and temporally resolved smoke concentration from which any number of toxic gases can be inferred. 

[NicoR]

Good morning,

I downloaded the latest version of FDS (6.7.7) yesterday and since then evacuation meshes are simply ignored by the software. Could it be that the removal of FDS+Evac from the code has already been done or am I the only one to have this problem?

When I try to add the extra MPI processor required for an evacuation mesh, I get an error that I am using too many processors for the job.

Please find an example code attached.

Regards,

Nicolas

[Gregor]

Version 6.7.7 is the last version in which FDS+Evac is implemented.

Good news, your described problem is probably user dependent. ;-) 

[Nicolas]

Ok. Could someone please try to run my code using version 6.7.7 then? I know it works with version 6.7.4 and have not read about any change in the way of declaring evacuation meshes.

Thanks in advance for your help.

[TimoK]

There has been already some discussion about the new and easier user inputs etc. for FDS+Evac.

I just copied some lines from a previous post below. The 6.7.6 and 6.7.7 versions will do the

fire+evacuation calculation in three steps: search EVACUATION_ALL_STEPS in this forum.

Now the .smv files can show agents and fire data easily: CHID_evac.smv shows just the

evacuation initialization phase ("fire drill"), CHID.smv shows just the results of the fire calculation,

and CHID_evmc.smv shows the result of fire+evacuation calculation.

Are you using FDS 6.7.6 or 6.7.7? If so, see:https://github.com/tkorhon1/FDS-Evac-Guide/blob/master/Manual/Readme.txt

Well, it might be that the readme file is for FDS 6.7.5, and 6.7.6 has a more user friendly way of doing things (search EVACUATION_ALL_STEPS in this forum).

Note, that your evacuation mesh has just 2 grid cells in the x-direction.

If you are using FDS 6.7.6:

EVACUATION_INITIALIZATION=.TRUE. phase: run just with one process (only evacuation meshes in the calculation)

EVACUATION_WRITE_FED=.TRUE. phase: run as a fire calculation without any evacuation (in your case 5 processes)

EVACUATION_MC_MODE=.TRUE. phase: run just with one process (only evacuation meshes in the calculation)

If you are using FDS6.7.5 (or older)

EVACUATION_DRILL=.FALSE., EVACUATION_MC_MODE=.FALSE. : number of processes = number of fire processes + 1

And with EVACUATION_DRILL=.TRUE. and/or EVACUATION_MC_MODE=.TRUE. number of processes = 1.

TimoK