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Author Topic: Simulation stopped due to "numerical instability"  (Read 8603 times)

otmal

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Simulation stopped due to "numerical instability"
« on: March 08, 2011, 01:48:07 am »

Hi

I'm trying to simulate a fire in a boat-storage, a large hall with ~80 boats. The simulation is done to see smoke quantities.
I want to know what a broken window does with fire and smoke development, so I made a hole with a "Control" to turn it on after a while. As soon as the window is created the simulation stops because of "Numerical instability".

Is there something I can do to prevent this from happening?

Øystein
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Charlie Thornton

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Re: Simulation stopped due to "numerical instability"
« Reply #1 on: March 08, 2011, 09:01:36 am »

Your question reminded me of a post about numerical instability on the FDS discussion group:

http://groups.google.com/group/fds-smv/browse_thread/thread/7d39ee2c0144acb6

In that discussion, Kevin mentions that to simulate a broken window, it may work better to include a buffer region between the outer bounds of your building and the bounds of the computational domain. My impression is that the trick is to have some transfer (leakage?) between the inside and the outside as opposed to suddenly opening an airtight container.
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otmal

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Re: Simulation stopped due to "numerical instability"
« Reply #2 on: March 09, 2011, 05:31:42 am »

Okay, I'll try to do so :)
Thanks!
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