Material property definition

[Rain_BabQ]

Hello, all the colleagues

Now, there's a project about museum fire protection design,
considering there are large animal specimens, such as heffalumps、
giraffes etc. I'll establish the fire model,but I can't define the HRR
value clearly, so I want to test this value, but now, the material
such as fur of the animals' is involved in this project. So i want to
know how to define the surface property,such as the &SURF lines in
FDS, please help me if who have the related dates.

Thank you,every one!

[Kevin]

Heffalump
From Wikipedia, the free encyclopedia

"In the [Winnie the Pooh childrens] books, Pooh and Piglet attempt
bravely to capture a heffalump in a trap. However, no heffalumps are
ever caught in their trap, and indeed they never meet a heffalump in
the course of the books. The sole actual appearance of heffalumps in
the books come as Pooh tries to put himself to sleep: "[H]e tried
counting Heffalumps [but] every Heffalump that he counted was making
straight for a pot of Pooh's honey ... [and] when the five hundred and
eighty-seventh Heffalumps were licking their jaws, and saying to
themselves, 'Very good honey this, I don't know when I've tasted
better', Pooh could bear it no longer." We learn nothing more about
the nature of the beasts in the writings."

I have seen Shepard's original sketches for the Winnie the Pooh books
in London, including the picture of the heffalump, but I do not recall
if Shepard or Milne listed the heffalump's thermophysical properties.
This is odd, because according to a brief biographical sketch:

http://www.just-pooh.com/milne.html

"Alan Alexander Milne was born on the 18th of January 1882 in
Hampstead, London. He was the youngest of three sons born to John Vine
Milne and Sarah Maria Heginbotham. His father was a schoolmaster at
the Henley House where Alan did get his first education. He continued
his education at Westminster School and Trinity College, Cambridge,
where he graduated with a degree in mathematics in 1903. Milne's first
literary efforts were published in the humorous magazine Punch, where,
in 1906 Milne started to work as Assistant Editor. In 1913 Milne
married Dorothy de Selincourt, the God-daughter of Punch editor, Owen
Seaman."

Milne was a mathematician! I wonder how the Pooh books survived peer
review. I suppose that children do not make good peer reviewers.

[Jonna]

Hehe, this post made my day :D good one!

> > Thank you,every one!- Hide quoted text -
>
> - Show quoted text -

[Simon Ham, FiSEC, UK]

Most stuffed animals are filled with plaster and the fur could
probably be represented sufficiently accurately by an approximation
equivalent to a thin layer of polyurethane foam, recognising that
Vitas would provide an extensive argument against this. Then again
there are those other products of an earlier mathematician, the
Jaberwocky and the Snark which may also be placed in the museum.
However if it also contained a specimen of the Boojam probably the
earliest recorded reference to a black hole the museum will disappear
negating any need for a model.

Oh well I must away to the 100 acre wood for a game of Pooh Sticks!

[Emanuele Gissi]

Can I quote this contribute in my project reviews?
So funny, so clear ;-)
Emanuele.

On Mar 26, 1:39 pm, Kevin <mcgra...@gmail.com> wrote:

> Heffalump
> From Wikipedia, the free encyclopedia
>
> "In the [Winnie the Pooh childrens] books, Pooh and Piglet attempt
> bravely to capture a heffalump in a trap. However, no heffalumps are

> ...

[Rain_BabQ]

Thanks for your reply. I think there'll be some problems in this
project, I have tried to establish the fire model inputs of FDS5, I
want to test the MAX heat release of the nature museum, in which there
are many kinds of animal's sample,because we don't define the HRR of
the scenario,so I want to test it by a given small fire(HRR) and using
it to ignite the animal's sample.Such as the elephant,the sample is
made up of three kinds of material, 30kg animal fur,10kg wood and 10kg
foam(after processed). I have defined the REAC line and the SURF
line,but I still think there are some improper notes.Please help me
and give me some comments.


&REAC ID = 'POLYURETHANE'
FYI = 'NFPA Babrauskas',
C = 6.30,
H = 7.10,
O = 2.10,
N = 1.00,
SOOT_YIELD = 0.1000 /

&MATL ID = 'fur'
FYI = 'Completely made up'
CONDUCTIVITY = 0.16
SPECIFIC_HEAT = 2.0
DENSITY = 50.
N_REACTIONS = 1
NU_FUEL = 1.
REFERENCE_TEMPERATURE = 250.
HEAT_OF_COMBUSTION= 22300.
HEAT_OF_REACTION = 2000. /

&SURF ID = 'FUR'
MATL_ID = 'fur'
BURN_AWAY = .TRUE.
COLOR = 'SILVER'
THICKNESS = 0.02 /

&MATL ID = 'FABRIC'
FYI = 'Properties completely fabricated'
CONDUCTIVITY = 0.1
SPECIFIC_HEAT = 1.0
DENSITY = 10.
N_REACTIONS = 1
NU_FUEL = 1.0
REFERENCE_TEMPERATURE = 280
HEAT_OF_REACTION = 3000.
HEAT_OF_COMBUSTION= 15000. /

&MATL ID = 'FOAM'
FYI = 'Properties completely fabricated'
CONDUCTIVITY = 0.05
SPECIFIC_HEAT = 1.0
DENSITY = 10.
N_REACTIONS = 1
NU_FUEL = 1.0
REFERENCE_TEMPERATURE = 280
HEAT_OF_REACTION = 1500.
HEAT_OF_COMBUSTION= 30000. /


&SURF ID = 'UPHOLSTERY'
FYI = 'Properties completely fabricated'
COLOR = 'MELON'
BURN_AWAY = .TRUE.
MATL_ID(1:2,1) = 'FABRIC','FOAM'
THICKNESS(1:2) = 0.002, 0.1 /


&MATL ID = 'spruce'
CONDUCTIVITY = 0.12
SPECIFIC_HEAT = 1.0
DENSITY = 50
N_REACTIONS = 1
NU_FUEL = 1.
HEAT_OF_REACTION = 1578.
HEAT_OF_COMBUSTION= 25200.
REFERENCE_TEMPERATURE = 250. /

&SURF ID = 'SPRUCE'
COLOR = 'PINK'
BURN_AWAY = .TRUE.
MATL_ID = 'spruce'
THICKNESS = 0.02 /


&SURF ID = 'burner'
COLOR = 'RED'
HRRPUA = 2000.
RAMP_Q = 'fire_ramp'/

&RAMP ID = 'fire_ramp', T = 0. , F = 0. /
&RAMP ID = 'fire_ramp', T = 10. , F = 1. /
&RAMP ID = 'fire_ramp', T = 1200. , F = 1. /
&RAMP ID = 'fire_ramp', T = 1201. , F = 0. /

[DavidShep]

Colleagues,

As we all know FDS can not accurately calculate heat release rate from
only material property inputs.

Currently the only method that can be accurately used for Heat Release
Rate inputs in FDS requires full-scale measurements using an oxygen
consumption calorimeter. As clearly described in the Users Guide, the
user takes the calorimeter data and develops a custom fire description
in the FDS input file.

A user could use the materials properties listed above in his model
and FDS would calculate a heat release rate. The resulting heat
release rate would be a made up number and would have no basis in
reality.

As we all know, some parts of FDS are ready to be used in production
work for building safety and life safety designs. Other parts of FDS,
like heat release rate predictions from material properties, are still
under development. These developmental parts of FDS should not be
used for building design work.

[Kevin]

Thanks, Eyore. You are right that it is not possible to reliably make
PREDICTIONS of burning rates with FDS, for a variety of reasons that
have been discussed in this forum. However, one of the frustrations
for me is that very few people use a simple technique that people like
Simo Hostikka, Chris Lautenburger, Guillermo Rein, and others, use to
quickly assess the validity of a given set of material properties.
Given that most, if not all, pyrolysis models assume that the heat
conduction is 1-D, normal to the surface, you can easily calculate, in
seconds or a few minutes, the response of your "virtual material" (as
Nick Dembsey calls it) to a given external heat flux. If you have cone
data, you can then compare your model prediction against an
experiment. Sure, it's not a perfect comparison, like the fire in the
cone changes the flux a bit, but at least this is a starting point. At
least you have some confidence that your assumptions about the
properties have some validity, and you also have a better sense of
what kind of error you can expect when you put your material
properties into a full-scale fire calc.

Even though we threw away the old FDS material database, I still get
the impression, based on the initial posting of this thread, that
practicing engineers still think that material properties for real, or
even imaginary, things exist, and it's just a matter of searching. But
the story of Pooh and Piglet searching in vain for the heffalump
should be seen as a metaphor for fire protection engineers searching
in vain for this fictional "database". It's not the data itself, but
rather the measurement techniques to get the data, that we need to
work on. There are as many materials in this world as there are plants
and animals found in that natural history museum. We'll never have a
comprehensive list of material properties, nor should we even try to
compile one. We should just make sure that the measurements are
clearly defined, relatively inexpensive to perform, and easily
transformed into model inputs.

[Rain_BabQ]

Thanks for your illumination.

> > used for building design work.- Hide quoted text -