Closed FabiaSchirinzi closed 1 year ago
Remove BURN_AWAY from the surfaces that can't actually burn away (i.e. all the Concrete surfaces). BURN_AWAY tells FDS that OBST is not permanent and HVAC needs its VENTs to be permanent. When I did that, FDS started time stepping
Note, even without HVAC, don't use BURN_AWAY unless needed. With BURN_AWAY, FDS has to allow for the possiblity that the OBST is removed one grid cell at a time. Doing this when it is not needed can slow down both FDS and Smokeview.
A few other comments:
-MPI works most efficiently when you divide the domain into cube-like sections rather than thin rectangles (the cost of MPI is exchange informatio at mesh boundaries). So rather than four 80x250x60 meshes, having four 160x125x60 meshes. -The default exterior boundary condition is INERT. You have OUTLETacc at the top of the structure and then one grid cell to a solid exterior boundary. -You have two small compartments that look like some kind of vestibule or airlock where it has small holes connecting to the larger compartments on either side. If this is meant to represent leakage, a better appraoch is to use the FDS leakage inputs (see the User's Guide). If these are actual holes, you may want to consider using the localized leakage method which will better capture the flow velocity when there are just a few grid cells across the opening.
Thank you for your help. I applied almost everything (I would like to fill the holes with a different material that I have to decide), but, when I start the simulation, the programme gives me "ERROR: numerical instability", without even starting the time steps. How is it possible that, unlike you, it doesn't work with me?
Are you running the current release (6.8.0)?
I am using 6.7.6 Do I have to download the last release?
Yes. Please download the last release.
It works, thank you so much!
Closing the issue since your case is working now.
I have a problem with the software, it keeps giving me the error that it can't find my inlet and outlet VENTS. Then, trying to change some parameters, sometimes the software stops at the reading stage. After inserting IOR in the VENTS (inserting it instead of UVW), FDS is blocked in the phase of: "Reading FDS input file...".
Looking at the geometry, FDS inserts my vents, so I can't understand why it isn't working.