Replies: 2 comments 5 replies
-
I think the larger issue is that you have defined what looks to be on the order of 1 m^3 OBST as being wood. Large dimensional wood is not easy to ignite (one starts a campfire first with small twigs and kindling and not the largest log available). If this is meant to be commodity attached to pallets and then stored on a rack or just stacked, it is likely the carboard and plastic of the commodity that is going to be the drive of firespread. Before jumping straight to a full warehouse domain, I suggest you limit yourself to a small number of columns of commodity and work on better definining properties that represent it. |
Beta Was this translation helpful? Give feedback.
-
Why should they be more different? Do a hand cacluation for the expected steady state temperatures for the front and back of each surface type. Does it indicate they should be more different? |
Beta Was this translation helpful? Give feedback.
-
Good morning everyone,
I know that the question I am going to ask is not really about how FDS works, but I wanted to ask your opinion based on your experience.
I am studying the evolution of a fire inside an industrial building in which wooden pallets are stored in order to determine the temperatures developing at the ceiling.
I have built the model, of which I attach photos from smokeview, in which each pallet has been schematized with an obstruction.
These obstructions are characterized by the material “wood” and follow, once ignited, a HRRPUA I entered.
By running the calculation model, it is evident that not all surfaces of the obstructions reach the ignition temperature (250°C) and therefore do not contribute to the total HRR. The result of the model are clear to me, also the heat transfer modes and other issues discussed here:
#12845
What I find incorrect, however, is my approach to the problem. In fact, I believe that in reality if one face of the pallet starts to burn due to pyrolysis and any dripping of materials, it is more conservative to consider that the whole pallet burns and therefore it is wrong to proceed with temperature ignition approach as I have done.
I think it is better to simplify the model a bit and insert obstructions equipped with appropriate VENT and relatice Control device that once they reach the ignition temperature (in this case estimated at 250°C) follow the defined HRRPUA.
What would you guys suggest ?
Thank you very much for any help.
Beta Was this translation helpful? Give feedback.
All reactions