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Topics - Michele

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PyroSim / Resume parallel simulation
« on: February 24, 2010, 07:20:21 am »
Resuming stopped simulations has problems at large meshes.
I''m actually working on a simulation with 300''000 cells, equally split in 2 meshes. The simulation runs in parallel mode (I have a dualcore CPU).
After stopping the simulation, the "resume parallel simulation" doesn''t work properly.
When doing the "resume parallel simulation", the "FDS simulation" windows opens properly and everything seems right. The "Time Elapsed" clock continues to increase , but the simulation does not restart, i.e. no further time steps are shown. I waited for 50 about minutes (confirmed by the Elapsed Time clock) and then had to close pyrosim manually.
This doesn''t happen when doing the non parallel "resume simulation", which restarts after a couple of seconds (even if applied to a previously parallel running simulation)
I tested both the 32 and 64 bit pyrosim versions, the former on a dualcore and the latter on a quadcore processor, with same results.
Somebody knows where is the problem on parallel simulations? Thanks


PyroSim / EVAC: Avatar color
« on: February 21, 2010, 02:20:30 pm »
In the EVAC Menu "evac -> properties -> output" one can define avatar color (both alive and death). By defining "Color By: PERS", the chosen colors should be seen in smokeview when activating the "SHOW/HIDE->Humans->HUMAN_COLOR".
The "death" color setup is working fine in smokeview, but not the alive avatar color, which remain in standard blue.
How can I see the desired avatar alive color?

PyroSim / Slab - crash
« on: February 12, 2010, 01:45:49 am »
when dealing with "SLAB" feature, Pyrosim crashes when the slab is outside the mesh boundaries.
The crash occur when trying to visualize the Record View, or when trying to run the simulaiton or even only by generating the FDS file.

By multiple meshes, same problem appears when the slab crosses 2 meshes, even though it remains inside the "global" mesh dimensions.
The only solution is to cut the slab in multiple pieces corresponding to mesh boundaries.

Attached the error report.

Thanks for the help

PyroSim / EVAC : disable mesh
« on: February 04, 2010, 02:47:20 pm »
I'm dealing with Evacuation simulation.
In order to test the set-up before proceeding with the complete simulation it is very useful to enable and disable the fire meshes and evacuation meshes.
In "common" fds code this can easily be done by deleting the ampersand ("&") from the unwanted mesh line.
In Pyrosim that's usually correspond to "disable" the selected object. It usually works but that function has no effect on the meshes (it can be seen from the source code).
Do I have to change some settings or that option doesn't work on Pyrosim?
Thanks for the help

PyroSim / Material definition
« on: February 03, 2010, 04:03:18 am »
In the description of material pyrolysis, the reaction rate formula is described with pressure (p).
It should be density (rho) as indicated in Chapter 3.4.3 of  Tech. Reference Guide, right?

PyroSim / EVAC : Random Seed
« on: February 02, 2010, 08:53:40 am »
in the Evac properties there is a flag possibility on "Use Random Seed".
When flagged, the FDS command "NOT_RANDOM=.TRUE." is added to the code line. The initial position and characteristics of the agents will therefore NOT chosen randomly (I suppose will be the same as the previous simulation).
This means that flagging the "Use Random Seed" results in NON-random agents selection (which is in contrast with the flag name...).

Is this interpretation correct?


PyroSim / Importing FDS+EVAC files
« on: February 01, 2010, 09:47:56 am »
I'm trying to import FDS+EVAC validation files "Case A" from, but every time Pyrosim crashes.
With "Case B" an error message is displayed ("Error in file ... For input string: "0.3" ").
All FDS files run with no problem if lounched from outside Pyrosim, so they should be correct written.
Can anyone help me?

PyroSim / Extinguishing coefficient
« on: February 01, 2010, 02:11:26 am »
Extinguishing coefficient in Pyrosim (E_COEFFICIENT in FDS) has unit [1/s].
Exact unit value should be m2/kg/s, right?

PyroSim / Initial Region Temperature vs Ambient temperature
« on: January 25, 2010, 04:54:59 am »
in FDS there is the possibility of having a region with initial temperature different from ambient temperature. The code line is like the following (example from "stack_effect" in FDS)
&INIT XB=0.5,0.8,2.1,3.4,2.5,3.6, TEMPERATURE=30. /
where the region XB is associated an initial air temprature of 30°C (ambient temperature can be default or other values)
Unfortunately this command is not recognized when importin the FDS file in Pyrosim.

Is there the possibility of having this command/action in Pyrosim?

thanks a lot

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