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 on: December 06, 2022, 02:19:59 am 
Started by Daniel Park - Last post by Daniel Park

I have been trying to conduct the hydrogen release and dispersion analysis in Pyrosim with making the Vent with Surface type as Supply.
In my understanding, hydrogen gas release is going upward through vertical vent outlet which is also upward direction.
However in pyrosim simulation, some of the gas cloud is going to downward unfortunately.

If anyone can help this issue, please let me know
I appreciate your help in advance.


 on: December 01, 2022, 10:21:53 am 
Started by Herr Wiedermann - Last post by Herr Wiedermann
Hello all,
I get the following error message although I selected the predefined reaction "POLYURETHANE".
Can someone help me here?
I use the following version "PyroSim 2022.2.0803".
Many thanks in advance

WARNING: SPEC REAC_FUEL is not in the table of predefined species. Any unassigned SPEC variables in the input were assigned the properties of nitrogen.

 on: November 30, 2022, 02:36:18 am 
Started by PimvR86 - Last post by PimvR86
Hi guys,

Whenever I try to enable a section box, both in the modeller and the viewer, Pyrosim exits without warning. This started when I installed the last update (2022.2.0803). I've updated my graphics driver as well, but alas, no improvements. Running it on this GPU:
Vendor: ATI Technologies Inc.
Renderer: AMD Radeon Pro WX3200 Graphics
OpenGL Version: 4.6.0 Compatibility Profile Context
GLSL Version: 4.60

Running simulations on a different setup. On that one, it runs as it should.

Hoping to hear your thoughts on this one.

Kind regards, Pim

 on: November 23, 2022, 09:16:57 am 
Started by Alex_IFAB - Last post by Alex_IFAB
Hi again,

If I select multiple rooms and add 10 occupants at random to them, I get 10 people distributed over the rooms. This is a nice feature as we are planning to simulate a high building with several 100 people and can simply say that 100 are at floor level and so on without saying how many are in which room.

But: If we start a Monte-Carlo simulation, the distribution of the people over the rooms stays the same. This means, if the room was empty in my initial file, it will be empty in all of the MC runs. The occupants are randomly distributed over the space in each individual room, but not over the rooms itself.
The image shows three MC runs as example, and the people are always distributed as 2-4-4.

Is there some way to get them truly randomized over the whole level of the building in the MC runs?


 on: November 23, 2022, 08:33:58 am 
Started by Alex_IFAB - Last post by Alex_IFAB

we are simulating the evacuation in trains and stations. As there are several objects in every part of the vehcile and people tend to are created within the geometry, we use the polygon tool to create rooms for the free space in the wagons. Using only the free space is necessary, because we evaluate the data from FDS for each person and this would be 0 for e.g. oxygen when the head is in an obstacle. The train is very crowded and we use sources to spawn the people over some time.

The occupants do not use the closest exit of the station ("Any exit behavior"), but a distribution over the exits. Therefore, they tend to run into each other and take some time to navigate through the vehicle. For this reason, we added "invisible walls" with open doors over the full length of the wall and sliced the vehicle into several connected rooms giving the occupants more grid points/doors for searching the closest path with A* search (locally quickest path, see

But: Now we have to define many sources for the occupants as each source can only have one room attached. Is there a way to define something like: "I want rooms A,B,C and F with 100 people source (in total, not individual for every room)" and "the other rooms get 400 in total"? Or would you recommend doing it completely different?


 on: November 14, 2022, 11:14:00 am 
Started by Bruce Slater - Last post by Bruce Slater
"Mathematical controls apply simple math operations on the selected input signals. Input signals may be any of Time, the output value of a device, a constant value, or the output of another Mathematical control."

When I tried to create a control that depends on the pressure differential of two statistics I was only able to choose Time, value of a device or constant.

How do I use another mathematical control?

 on: November 12, 2022, 10:23:24 am 
Started by g.jaeger - Last post by insharazzak
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 on: November 07, 2022, 05:59:00 am 
Started by g.jaeger - Last post by g.jaeger
A low-pass filter is used to plot the door flow rate. This is used as the default (UG, 15.2.1).

Why is this filter method used as default and not the moving average? I only know this low-pass filter from control engineering/elctrotechnics.

 on: November 07, 2022, 01:30:52 am 
Started by EvaSmith - Last post by EvaSmith
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 on: October 27, 2022, 02:37:30 pm 
Started by rubyrobinson555 - Last post by rubyrobinson555
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