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 91 
 on: July 28, 2020, 09:23:36 am 
Started by Perera - Last post by Perera
Hello Everyone,

I have modeled a fire which is to be ignited by a burner surface (burner surface only for first 10 seconds), to be spread thereon and to be extinguish with the sprinklers.
But after sprinklers activated the fire getting reduced but not extinguish completely. I have run the simulation for 250 seconds but fire continue at a lower level not getting extinguish.
Is there any possibility in Pyrosim to model a fire that get extinguish completely with sprinklers Or have I defined the values incorrectly?

And please find the below link for the model (.psm) for you reference

https://we.tl/t-obPotXi9Kk

Thanks

 92 
 on: July 27, 2020, 04:13:42 am 
Started by Perera - Last post by Perera
Thanks Dave,

My model was initially modeled through Revit and I have made a mistake when exporting to CAD. Below quote helped me to solve the problem.

"In the Modify DWG/DXF Export Setup dialog, select the Solids tab, and select ACIS solids. This option allows PyroSim to import objects as solid obstructions rather than treating each exported face as a thin obstruction"

Thanks again   :)

 93 
 on: July 27, 2020, 12:29:47 am 
Started by Csaba_90 - Last post by Csaba_90
I am using Pyrosim v2020.20527. When running a simulation with ESFR sprinklers (or with normal sprinklers) protecting a multifunctional sport hall the simualtion stops (depending on the activation of sprinklers) with the following error message:
WARNING Delta TMP_G. Mesh: 23 Particle: 1
WARNING TMP_G_N < TMP_D_N. Mesh:23 Particle: 1
(I'm looking for the problem source and find that the message means that during the temperature update of a particular grid cell in Mesh 23, the droplet whose index is 1 caused the cell gas temperature (TMP_G) to change too rapidly.)
This error message string is repeated several times for differt particle IDs. The common event the calculation stops for a while (with this error message) and it continues. At random event when the error message occur the calculation stays (at that moment when the message apeear) for days.

I couldn't find the correct solution so far. However i tried the following according to the fds user guide:
- on the MISC. line set PARTICLE_CFL= TRUE (the result was the calculation extremely slowed about 1100 sec the problem occured)
- changed the PARTICLES_PER_SECOND on the prop line from 5000 to 20000 (same result)

This problem didnt occured on the previous versions. Running the case with MPI. Does anyone has the same problem or the correct solution?

Thank you.

 94 
 on: July 24, 2020, 03:18:18 pm 
Started by Perera - Last post by Dave McGill
I started it, and it ran.

 95 
 on: July 24, 2020, 10:01:05 am 
Started by Andrés Felipe Cardoso - Last post by Andrés Felipe Cardoso
Thanks Dave, your timely response has been very helpful, thank you very much for your kindness.

Felipe

 96 
 on: July 24, 2020, 07:42:43 am 
Started by AnnikaHH - Last post by AnnikaHH
Hello,

I was evaluating the results of the occupants velocities in occupants_detailed.csv file for every time step. There are time steps at which the velocities of some occupants are much too high (max value is nearly 9 m/s which is around 5 times the maximum input velocity). In the Pathfinder Results Simulation File, this high velocity can't be seen, the occupants seems to have a normal and realistic velocity.
It seems to happen especially for occupants which are assisting a wheelchair.

Can someone tell me if this is a bug or if there is something I can do to avoid this miscalculation in the result file?

Thanks.
Annika

 97 
 on: July 23, 2020, 05:27:18 pm 
Started by Andrés Felipe Cardoso - Last post by Dave McGill
Hi Felipe,

There are a couple of obvious issues.

1. There is one mesh with over 3 million cells. There is no way that can run. Sub-divide it to match the number of processors you have.

2.  The model and mesh are located, literally, hundreds of km from the origin, in all three dimensions. (See the attached image.) You've probably run up against a limit of either FDS or PyroSim. Use the copy/move feature to put the lower left corner of the mesh on the origin (0,0,0).

Dave

 98 
 on: July 23, 2020, 02:58:14 pm 
Started by Andrés Felipe Cardoso - Last post by Andrés Felipe Cardoso
Good afternoon , my name is Felipe

I have problems in the results , because when sensors such as thermocouples are placed, at the moment of obtaining the complete results of the simulation, it happens that the screen appears as if it did not obtain results, only if view tours are clicked, but by simulating without the sensors the model throws out a normal simulation, I would like to know what the problem is?

Thanks for your help and time, have a good day.

Sincerely,

Felipe

 99 
 on: July 23, 2020, 02:46:39 pm 
Started by 4rthur - Last post by Dave McGill
That is a very ambitious project for a beginner. I suggest you read Dan Swenson's notes on modelling jet fans.

https://www.thunderheadeng.com/?s=jet+fans

 100 
 on: July 23, 2020, 04:02:26 am 
Started by 4rthur - Last post by 4rthur
Hello, I am currently working on a model of underground garage with jet fans.

I have also plenty of other questions I would like to ask, I'm totally new to PyroSim, so:
1. I'm working with PyroSim 2015.3.0810. Do you recommend any specific FDS and Smokeview versions?
2. The garage geometry isn't so simple, but I created a simple rectangular mesh and used blocks to separate space outside the parking (like staircases, storage rooms etc.). Should I make multiple meshes (a lot of large and small meshes combined) instead? Which option will give better/faster results?
3. Can someone explain me step by step how to simulate a fire of 3 cars according to NEN 6098:2010.
These are the most important questions for now  :-[

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