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Consolidated Model of Fire and Smoke Transport
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How to tell CFAST how much material to burn is there? #2052

Closed KathMich93 closed 1 year ago

KathMich93 commented 1 year ago

I have a question: How can I tell CFAST how much burning fuel there is for the fire? I only know about the chemical atoms C, H, O, N and CL, but that is not the material which burns? I would like to tell CFAST how much material is there which can burn. Or do I have to say it with the walls? But we don't have a weight or a mass for the walls, only measures? Thank you.

KathMich93 commented 1 year ago

Might the amount of burning fuel be the area of the fire? As anything which is on the ground of the fire is what burns somewhen?

mcgratta commented 1 year ago

You specify the heat release rate as a function of time. If you know the heat of combustion, this will enable you to specify the total mass of fuel that is burning.

Also, use the Discussion Group for this kind of question. The Issue Tracker is for bug reports.

preneke commented 1 year ago

CFAST doesn't model how a fire burns. It models the impact of a fire on a structure. The fire is a number of inputs, most importantly the Heat Release Rate HRR. That determines when and how much fuel burns at each instant in the fire. The chemical composition is used to determine the composition of the smoke from the fire not the HRR. The HRR and the Heat of Combustion HOC determines how much fuel is burnt.

From: KathMich93 @.> Sent: Thursday, May 25, 2023 4:59 AM To: firemodels/cfast @.> Cc: Subscribed @.***> Subject: Re: [firemodels/cfast] How to tell CFAST how much material to burn is there? (Issue #2052)

Might the amount of burning fuel be the area of the fire? As anything which is on the ground of the fire is what burns somewhen?

- Reply to this email directly, view it on GitHubhttps://github.com/firemodels/cfast/issues/2052#issuecomment-1562538534, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ADDV4MHLJGNGAOFNFEQ3FH3XH4NLNANCNFSM6AAAAAAYOQDKKY. You are receiving this because you are subscribed to this thread.Message ID: @.**@.>>

KathMich93 commented 1 year ago

Thank you. Where do I find the discussion group? I haven't seen it so far. Yes, the HRR shows how much of the fuel burns. But what does show how much fuel actually is there which can burn?

drjfloyd commented 1 year ago

https://groups.google.com/g/cfast

How much fuel is there is an input that you provide. As the model user, it is up to you to determine what fuel load is appropriate for analysis.

KathMich93 commented 1 year ago

Thank you. In the example case, I read a column with Fuel, but there is only the chemical formula like C9H6O2N2. How can I increase or decrease it? Wouldn't it become a different chemical thing if I change the amount of molecules? For example, if I want to have wood or concrete as burning material. How can I describe that as burning fuel? For example, if I have 2kg of it. How can I describe that?

drjfloyd commented 1 year ago

Please use the forum for questions on using CFAST.

KathMich93 commented 1 year ago

I filled in a request to take part in the group.

KathMich93 commented 1 year ago

As Katharina Michaelis.

KathMich93 commented 1 year ago

I am sorry, I don't find a button to reply to a post in the cFast google group, or how to create a new post there, even though I am a member there now... I would need a solition till tomorrow... Could you please reply me here instead if you know something? I am sorry...

Jason Floyd @.***> schrieb am Do., 25. Mai 2023, 16:12:

Please use the forum for quetiosn on using CFAST.

— Reply to this email directly, view it on GitHub https://github.com/firemodels/cfast/issues/2052#issuecomment-1562983668, or unsubscribe https://github.com/notifications/unsubscribe-auth/A73UHR3DMIAT3WSLQBARWD3XH5SEJANCNFSM6AAAAAAYOQDKKY . You are receiving this because you authored the thread.Message ID: @.***>

drjfloyd commented 1 year ago

Use a PC to connect to the group or if on your phone choose to load the full web version. The mobile version of groups sometimes has issues.

KathMich93 commented 1 year ago

I already tried...

Jason Floyd @.***> schrieb am Do., 25. Mai 2023, 21:21:

Use a PC to connect to the group or if on your phone choose to load the full web version. The mobile version of groups sometimes has issues.

— Reply to this email directly, view it on GitHub https://github.com/firemodels/cfast/issues/2052#issuecomment-1563397329, or unsubscribe https://github.com/notifications/unsubscribe-auth/A73UHR4BMZN4OHQ4JAWRPD3XH6WLVANCNFSM6AAAAAAYOQDKKY . You are receiving this because you authored the thread.Message ID: @.***>

mcgratta commented 1 year ago

We are going to stop using Google Groups within the year, so if it gives you trouble, you can continue to use the Issue Tracker.