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Author Topic: flashover fire  (Read 1965 times)

Zugin

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

Hello,

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,

Kamil


Edit:

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 :

« Last Edit: April 06, 2017, 03:19:06 am by Zugin »
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Jared

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Re: flashover fire
« Reply #1 on: April 06, 2017, 07:07:00 pm »

I want to initially caution you on what you are going to use the results of this fire model for.  While fire spread is possible to model in FDS, it is mostly unvalidated due partially to the incredible amount of variables which affect spread.  One of the materials you have picked even has a "CAUTION" note due to its missing validation in the "FYI" field.

Without seeing the results or layout of the model it is tough to understand exactly what is going wrong or what you expect to happen in the model. 
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Zugin

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Re: flashover fire
« Reply #2 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..


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


EDIT 2:

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")
« Last Edit: April 07, 2017, 02:00:34 am by Zugin »
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