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Messages - Zugin

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PyroSim / Re: Invisible wall between meshes?
« on: May 12, 2020, 05:04:55 am »
So, I moved the meshes forward (so now, it's not divided under smoke curtain, it's divided further) and here is the result (attached) as I told earlier - 2 meshes. One 0,4x0,4x0,4 2nd one 0,8x0,8x0,8 on their conection the problem occurs.

PyroSim / Invisible wall between meshes?
« on: May 11, 2020, 05:38:21 am »
So i have such problem:

I have really huge open space in which I want to simulate smoke spread. In huge shortcut I devided model like this:
1) everywhere near the fire I have mesh 0,4x0,4x0,4, meshes with such dimensions ends on smoke curtain.
2) after smoke curtain I have everywhere 0,8x0,8x0,8.

Here is the problem. The fire spread normally for 100-120 secs. After that the velocities are spreading normally only in my 0,4x0,4x0,4 meshes. On 0,8x0,8x0,8 meshes it looks like the velocities are nearly 0m/s. The smoke on Y visibility slice looks like there is an invisible wall (?)(attached 2 screenshots). After opening my smoke vents (I am opening it by "controler" and deactivation obstacles) and aeration holes it looks like this "invisible wall" disappears ?

Really, I tried almost everything. Changed the meshes dimensions, changed the place, dimensions and HRRPUA of burner vent.

I attached pictures of situation before the ventilation starts and 20 s after smoke ventilation system starts work.

Can you help me? Maybe show me where I am making mistake?

PyroSim / Re: fire spread and heat radiation
« on: April 13, 2017, 06:13:55 am »

I had the same problem. I'm not sure if that's a good way, but :
I was trying to make simulation, on which I will have heat radiation on walls (how fire affect walls through the window). I used radiative heat flux boundary. I don't know how to see area of spread and radiation (without any geometry), but i made a wall in 1m from the window, and i can see now, a temperature on wall. It is worse idea, because i wanted see how it affect on every wall - i have 6walls at intervals of 1m - now I need to have 6 simulations, but at least it works.
I'm really interested how to make such model as you sent, but i hope that something i just wrote here may help you.

PyroSim / Re: flashover fire
« on: April 07, 2017, 01:18:22 am »
Yeah, i know that. I'm just trying to get this. The caution thing is while you pick "foam" from library. That was 1st thing
2nd thing is that: Is it better to simulate a fire by using HRR ?

Here are some pics from model and from smokeview:
as you can see on smokeview screen, my bed is in flames, but table or chair still didn't light up. I just want to know how to light up everything i can in that room..

Well, I'd like to do something like this screen's name "flashover" :


In on of my simulations i have a situation where my foam is disappearing cell-by-cell - and this is ok, i wanted to do this, but wooden construction below the bed isn't disappearing and it looks like it isn't even flammable. (as on the screenshot "not flammable")

PyroSim / flashover fire
« on: April 06, 2017, 03:00:06 am »

I'm a student, who is trying to make model in which fire in smokeview can "move" from for example table and make that bed will light up because of pyrolisis/temperature.

I already set up :
- materials (wood and foam in which i edited reactions and let the fire spreading up through the layers of furniture) i set up also heat of reaction (endothermic) and heat of combustion.
- reaction ( i didn't limit the fire, and didn't set up anything in "advanced" i set up rest - fuel and "according to attribute of material")
- Maybe i made mistake somewhere in surfaces, but i can't find it out.

Here are my questions
1. What is going on with pyrolisis range ? i can't get this
2. How about radiative fraction ? is that thing that let me spreading my fire?
3. What can i do to let my fire "spread" on rest furniture in the room?
4. What else information do you need to help me with this problem? I saw NEST's fds examples, but when i'm trying to open it, I have a question: on which fds 4 5 or 6 i want to run it. No metter which one i choose, something will be missing for example reaction. I don't know how to handle it, because i heard that these examples may help me with understanding this.

Maybe you could tell me what I'm supposed to do, to have experimental fire which will spread and "jump" from furniture to furniture, and make cell-by-cell burn into elements of interior design.

Best regards,



Do I need to set up in which temperature for example wood should light up? If yes, where i can find those informations?

These are information from FDS save- way :

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