FDS and Smokeview Discussions Google Group

Re: Why I can not get a nice t-squared HRR curve?

drjfl...@gmail.com (dr_jfloyd) — Fri, 08 Jan 2010 04:05:16 UT

FDS is a computational fluid dynamics code. It is not a zone model
like CFAST, it is not a spreadsheet based correlation. Fuel does not
burn in FDS until it mixes with oxygen under conditions that meet the
flammability requirements of the combustion model. If you specify a
fire that is not capable of burning under the ventilation conditions

Re: Why I can not get a nice t-squared HRR curve?

yunlo...@gmail.com (Jason) — Fri, 08 Jan 2010 01:00:33 UT

I have uploaded the FDS5.4.2 calculated HRR "T-Sqaured-HRR-
FDS5.4.2.pdf".
It's strange to me. The should have a way to force a t-squared curve.

Re: install help required

gfor...@gmail.com (Glenn Forney) — Thu, 07 Jan 2010 18:09:15 UT

start an issue on the issue tracker. Make sure you tell us what type
of linux install you are using (particularly whether it is 32 or 64
bit) Also attach your pplume5.smv file . Note that if you are using a
64 bit computer/OS both the 32 and 64 versions of FDS will run.
However, only a 64 bit version of Smokeview will run on a 64 bit

Re: inquire

f.braennstr...@gmx.de (Fabian Braennstroem) — Thu, 07 Jan 2010 18:03:12 UT

Hi,
even for RANS models, this would be not suitable and using a symmetry in
LES is not suitable...
Fabian

Re: inquire

f.braennstr...@gmx.de (Fabian Braennstroem) — Thu, 07 Jan 2010 18:03:01 UT

Hi,
even for RANS models, this would be not suitable and using a symmetry in
LES is not suitable...
Fabian

Re: Fds+blender+gbXML?

wyldc...@gmail.com (wyldckat) — Thu, 07 Jan 2010 16:23:46 UT

Hi Fabian,
We use snappyHexMesh frequently in our project that gbXML2STL comes
from. The first iteration of snappyHexMesh does it's first approach as
a cartesian mesh, based on the enveloping base mesh. A bit of "target
practice" for the base mesh might actually provide a very good
approach to making an adjusted mesh to the room. The openings are

Re: fds accuracy/convergence/stability

mcgra...@gmail.com (Kevin) — Thu, 07 Jan 2010 16:11:43 UT

The algorithms are different. Suppose you have an incompressible flow,
del dot u = 0. The momentum equation in FDS is written
rho du/dt + F + grad p = 0
Since rho is constant (in this example, not in general), you can take
the divergence of the equation
del^2 p = -div dot F
FDS solves this equation using a direct Poisson solver, so that when

Re: Problem using for Window 64 bit

mcgra...@gmail.com (Kevin) — Thu, 07 Jan 2010 15:51:44 UT

Whenever you have trouble with the 64 bit version of FDS, try the 32
bit version. If that fails, submit the case to the Issue Tracker.

Re: inquire

mcgra...@gmail.com (Kevin) — Thu, 07 Jan 2010 15:47:21 UT

You cannot do that. Just add the ISOF line and you will get output for
all meshes.

Re: Leakage location

mcgra...@gmail.com (Kevin) — Thu, 07 Jan 2010 15:45:19 UT

The idea of the leakage model is to approximate the leak from a
compartment that is not necessarily concentrated in one place. I
usually apply the leak area to the entire wall, or door, or whatever.
It was not designed to distinguish between the floor and ceiling. It
might be possible to include local pressure or stratification effects,

Re: fds accuracy/convergence/stability

julien.hassan...@gmail.com (Julien) — Thu, 07 Jan 2010 15:09:04 UT

I made a mistake in my previous message.
In the second line the word "converged" as to be replaced by
"correct".
Sorry,
Julien
Julien a écrit :

Re: fds accuracy/convergence/stability

julien.hassan...@gmail.com (Julien) — Thu, 07 Jan 2010 15:01:15 UT

Christopher,
I totally agree with you. If the residuals reach the trigger values,
that does not mean that the solution is "converged". However, in my
opinion, monitoring these values (without setting any trigger level)
is important and give a first clue of the "goodness" of the solution.
In a nutshell, my original question was: As there is no way to monitor

Re: Fds+blender+gbXML?

f.braennstr...@gmx.de (Fabian Braennstroem) — Thu, 07 Jan 2010 13:36:53 UT

Hi Bruno,
as you are already using OpenFOAM... do you have experience with
snappyHexMesh and what do you think about it's ability to create
cartesian meshes based on STL geometries? With some additional
programing this might be quite powerful for FDS 'OBST' approach (though
I am not sure, if FDS is able to handle hanging nodes with its FFT solver)?

Re: How to simulate a fire of highland

randy.mcderm...@gmail.com (rmcdermo) — Thu, 07 Jan 2010 13:23:49 UT

Ann,
Search the User's Guide for P_INF and Y_O2_INFTY.
Cheers,
R

Re: More on RESTART 'issues'

christopher.w...@firelinkllc.com (cwood) — Thu, 07 Jan 2010 12:40:18 UT

I would use the time to calculate the 100 steps, when FDS normally
outputs a message about status, as a guide from the .out file. I have
not previously done timings with reading in the restart file, but
would look at the number of cells, meshes and particles. I would then
have to make an estimate about setup time, but I do not have a