[fds-smv] using multi layered surface
1,181 views
Skip to first unread message
chemboy
May 12, 2010, 10:50:17 AM5/12/10
to FDS and Smokeview Discussions
I am wondering if some one could tell me how can i draw a box with two
layers of different materials. I am facing problem in setting the
value of parameter ''THICKNESS'' on SURF line.
&MESH IJK=20,20,20 XB=0.0,1.0,0.0,1.0,0.0,1.0 /
&OBST XB=0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID='FOAM SLAB' /
&SURF ID = 'FOAM SLAB'
MATL_ID (1,1) = 'FOAM'
MATL_ID (2,1) = 'FOAM'
THICKNESS = 0.1, 0.2/
By looking at the obstruction please let me know what should be the
appropriate values of thickness of layer1 and layer2.
secondly do you expect that with the above mentioned code same results
will be obtained as in case of single layer material. (As i have just
changed the number of layers but both layers are of same material)
i am not getting the same results please help me out of this what is
the problem with the file?
thank you in anticipation
--
You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
To post to this group, send email to fds...@googlegroups.com.
To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/fds-smv?hl=en.
layers of different materials. I am facing problem in setting the
value of parameter ''THICKNESS'' on SURF line.
&MESH IJK=20,20,20 XB=0.0,1.0,0.0,1.0,0.0,1.0 /
&OBST XB=0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID='FOAM SLAB' /
&SURF ID = 'FOAM SLAB'
MATL_ID (1,1) = 'FOAM'
MATL_ID (2,1) = 'FOAM'
THICKNESS = 0.1, 0.2/
By looking at the obstruction please let me know what should be the
appropriate values of thickness of layer1 and layer2.
secondly do you expect that with the above mentioned code same results
will be obtained as in case of single layer material. (As i have just
changed the number of layers but both layers are of same material)
i am not getting the same results please help me out of this what is
the problem with the file?
thank you in anticipation
--
You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
To post to this group, send email to fds...@googlegroups.com.
To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/fds-smv?hl=en.
Kevin
May 12, 2010, 11:43:32 AM5/12/10
to FDS and Smokeview Discussions
Your grid is fine enough to resolve the layers. Just create the box
from multiple obstructions.
from multiple obstructions.
dr_jfloyd
May 12, 2010, 12:00:06 PM5/12/10
to FDS and Smokeview Discussions
FDS does not do OBST to OBST conduction heat transfer. So a SURF of
two layers is not at all equivalent to two back to back SURF of one
layer.
two layers is not at all equivalent to two back to back SURF of one
layer.
Kevin
May 12, 2010, 12:05:01 PM5/12/10
to FDS and Smokeview Discussions
Yes, good point. Another alternative is then:
&SURF ID = 'FOAM SLAB'
MATL_ID (1,1) = 'FOAM'
MATL_ID (2,1) = 'FOAM'
MATL_ID(3,1) = 'FOAM'
BACKING = 'EXPOSED'
THICKNESS = 0.1, 0.2, 0.1/
but keep in mind that the 1-D heat conduction assumption is not
particularly good in this case.
> For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.- Hide quoted text -
>
> - Show quoted text -
&SURF ID = 'FOAM SLAB'
MATL_ID (1,1) = 'FOAM'
MATL_ID (2,1) = 'FOAM'
BACKING = 'EXPOSED'
THICKNESS = 0.1, 0.2, 0.1/
but keep in mind that the 1-D heat conduction assumption is not
particularly good in this case.
>
> - Show quoted text -
chemboy
May 12, 2010, 12:32:51 PM5/12/10
to FDS and Smokeview Discussions
HELLO
i tried with your suggetions but sorry it didnot work.
THICKNESS = 0.05
BURN_AWAY = .TRUE.
BACKING = 'EXPOSED' /
0.05 is a default value of thickness in the file box_burn_away.fds.
using this thickness whole box burnt within 40 sec.
But after applying your suggestions very very few material get burnt
in 60sec. FDS is not giving same results for two cases.
i wish you to check the file box_burn_away.fds in your FDS directory.
it is a very short simulation and will take much of your time.
please also give any other workable suggetion/idea.
thank you in anticipation
On 12 Maj, 18:05, Kevin <mcgra...@gmail.com> wrote:
> Yes, good point. Another alternative is hadeeth:
>
> & SURF ID = 'FOAM SLAB'
> Thickness = 0.1, 0.2, 0.1 /
>
> But keep in mind thats the 1-D heat conduction Assumption ice note
> Particularly good in this case.
>
> On May 12, 12:00 pm, dr_jfloyd <drjfl...@ Gmail.com> wrote:
>
>
>
>
>
> > Does FDS note to do Obst Obst conduction heat transfer. So of a SURF
> > Two layers Is Not at all equivalent to Two back to back one of SURF
> > Layer.
>
> > 12 On May, 11:43 am, Kevin <mcgra...@ Gmail.com> wrote:
>
> >> Your grid is refined Enough to Resolve the layers. Just create the box
> >> From multiple obstruction.
>
> >> On May 12, 10:50 am, chemboy <ASIM...@ Gmail.com> wrote:
>
> >>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>> Different layers of materials. I Am Facing problems in setting the
> >>> Value of the parameter''thickness''on SURF line.
>
> >>> & MESH IJK = 20,20,20 XB = 0.0,1.0,0.0,1.0,0.0,1.0 /
> >>> Obst & XB = 0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID = 'FOAM SLAB' /
> >>> & SURF ID = 'FOAM SLAB'
>
> >>> Village looking at the obstruction please let me know what Should Be The
> >>> Appropriate Values of thickness of layer1 and layer2.
>
> >>> Secondly do you expect That with the Above mentioned code Sami results
> >>> Will Be obtained as in case of single-layer materials. (As i have just
> >>> Changed the number of layers But Both layers are of materials Sami)
>
> >>> I am not getting the results Sami please help me out of this what-ice
> >>> The problems with the file?
> >>> Thank you in Anticipation
>
> >>> -
> >>> Received You thismessage Because You are Subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>> To this group to post, send email to fds...@googlegroups.com.
> >>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >> You Received thismessage Because You are subscribed to the the Google Groups "FDS and Smoke View Discussions" group.
> >> To post to this group, send emails to fds...@googlegroups.com.
> >> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> > You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hide quoted text -
> For More Options, Visit this group clickhttp://groups.google.com/group/fds-smv?hl=en.- Hide quoted text -
i tried with your suggetions but sorry it didnot work.
THICKNESS = 0.05
BURN_AWAY = .TRUE.
BACKING = 'EXPOSED' /
0.05 is a default value of thickness in the file box_burn_away.fds.
using this thickness whole box burnt within 40 sec.
But after applying your suggestions very very few material get burnt
in 60sec. FDS is not giving same results for two cases.
i wish you to check the file box_burn_away.fds in your FDS directory.
it is a very short simulation and will take much of your time.
please also give any other workable suggetion/idea.
thank you in anticipation
On 12 Maj, 18:05, Kevin <mcgra...@gmail.com> wrote:
> Yes, good point. Another alternative is hadeeth:
>
> & SURF ID = 'FOAM SLAB'
> MATL_ID (1,1) = 'FOAM'
> MATL_ID (2,1) = 'FOAM'
> MATL_ID (3,1) = 'FOAM'
> Backing = 'Exposed'
> MATL_ID (2,1) = 'FOAM'
> MATL_ID (3,1) = 'FOAM'
> Thickness = 0.1, 0.2, 0.1 /
>
> But keep in mind thats the 1-D heat conduction Assumption ice note
> Particularly good in this case.
>
> On May 12, 12:00 pm, dr_jfloyd <drjfl...@ Gmail.com> wrote:
>
>
>
>
>
> > Does FDS note to do Obst Obst conduction heat transfer. So of a SURF
> > Two layers Is Not at all equivalent to Two back to back one of SURF
> > Layer.
>
> > 12 On May, 11:43 am, Kevin <mcgra...@ Gmail.com> wrote:
>
> >> Your grid is refined Enough to Resolve the layers. Just create the box
> >> From multiple obstruction.
>
> >> On May 12, 10:50 am, chemboy <ASIM...@ Gmail.com> wrote:
>
> >>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>> Different layers of materials. I Am Facing problems in setting the
> >>> Value of the parameter''thickness''on SURF line.
>
> >>> & MESH IJK = 20,20,20 XB = 0.0,1.0,0.0,1.0,0.0,1.0 /
> >>> Obst & XB = 0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID = 'FOAM SLAB' /
> >>> & SURF ID = 'FOAM SLAB'
> >>> MATL_ID (1,1) = 'FOAM'
> >>> MATL_ID (2,1) = 'FOAM'
> >>> Thickness = 0.1, 0.2 /
> >>> MATL_ID (2,1) = 'FOAM'
>
> >>> Village looking at the obstruction please let me know what Should Be The
> >>> Appropriate Values of thickness of layer1 and layer2.
>
> >>> Secondly do you expect That with the Above mentioned code Sami results
> >>> Will Be obtained as in case of single-layer materials. (As i have just
> >>> Changed the number of layers But Both layers are of materials Sami)
>
> >>> I am not getting the results Sami please help me out of this what-ice
> >>> The problems with the file?
> >>> Thank you in Anticipation
>
> >>> -
> >>> Received You thismessage Because You are Subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>> To this group to post, send email to fds...@googlegroups.com.
> >>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >> You Received thismessage Because You are subscribed to the the Google Groups "FDS and Smoke View Discussions" group.
> >> To post to this group, send emails to fds...@googlegroups.com.
> >> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> > You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hide quoted text -
>
> > - Show quoted text -
>
> -
> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> > - Show quoted text -
>
> -
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> For More Options, Visit this group clickhttp://groups.google.com/group/fds-smv?hl=en.- Hide quoted text -
dr_jfloyd
May 12, 2010, 12:54:24 PM5/12/10
to FDS and Smokeview Discussions
Have you read section 8.4.6 of the User's Guide?
> > > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hidequoted text -
>
> > > - Show quoted text -
>
> > -
> > You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> > For More Options, Visit this group clickhttp://groups.google.com/group/fds-smv?hl=en.-Hide quoted text -
> > > - Show quoted text -
>
> > -
> > You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>
> > - Show quoted text -
>
> > - Show quoted text -
>
chemboy
May 13, 2010, 5:10:38 AM5/13/10
to FDS and Smokeview Discussions
Yes i have read the section 8.4.
The box_burn_away.fds (can be found in your FDS installation directory
under the folder FIRES) is a simple test case prepared under the guide
lines of secion 8.4.
I have make a small change in that file that i keep the volume of box
constant but just add multiple layers of same material. It is expected
that FDS should give same results once again.
But it is not a case. What i found is that FDS simulation is very
sensative to THICKNESS of layer on SURF line. I tried with different
thicknesses. some time box gets burnt and some time it didnot get
fully burnt at all.
I donot know how FDS is handling with it.
On May 12, 18:54, wrote dr_jfloyd <drjfl...@gmail.com>:
>
>
>
>
>
>> HELLO
>> I tried with your suggetions sorry But it didnot work.
>
>> Thickness = 0.05
>> = BURN_AWAY. TRUE.
>> Backing = 'Exposed' /
>
>> 0:05 is a default value of thickness in the file box_burn_away.fds.
>> Using this box thickness Whole Burnt Within 40 sec.
>> But after applying your suggestions very very Few materials goat Burnt
>> In 60sec. FDS Is Not Giving Sami results for Two Cases.
>> I wish you to check the file in your directory box_burn_away.fds FDS.
>> It is a very short simulation and Will take much of your time.
>> Also please give Any Other work variable suggetion / IDEA.
>> Thank you in Anticipation
>
>>>> Does FDS Note to do Obst Obst conduction heat transfer. So Of A SURF
> >>>>> Will Be obtained-as in case of single-layer materials. (As i have just
>
>>>>> -
>>>>> You Received thismessage Because You are subscribed to the the Google Groups "and FDS Smoke View Discussions" group.
>
>>>> -
>>> You Received Because thismessage You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>> To unsubscribe from this Group, send email to fds-SMV + unsub...@googlegroups.com.
>>> For More Options, click Visit this group http: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequoted text -
>> To unsubscribe from this group, send email to SMV fds + unsub...@googlegroups.com.
>> For more options, Visit this group click http: / / groups.google.com / group / fds-SMV? Hl = en.
>
> -
> You Received thismessage Because You are subscribed To The Google Groups "FDS and Smoke View Discussions" group.
The box_burn_away.fds (can be found in your FDS installation directory
under the folder FIRES) is a simple test case prepared under the guide
lines of secion 8.4.
I have make a small change in that file that i keep the volume of box
constant but just add multiple layers of same material. It is expected
that FDS should give same results once again.
But it is not a case. What i found is that FDS simulation is very
sensative to THICKNESS of layer on SURF line. I tried with different
thicknesses. some time box gets burnt and some time it didnot get
fully burnt at all.
I donot know how FDS is handling with it.
On May 12, 18:54, wrote dr_jfloyd <drjfl...@gmail.com>:
> Have you read section 8.4.6 of the User's Guide?
>
> On May 12, 12:32 pm, chemboy <ASIM...Gmail.com> wrote:
>
>
>
>
>
>
>> HELLO
>> I tried with your suggetions sorry But it didnot work.
>
>> Thickness = 0.05
>> = BURN_AWAY. TRUE.
>> Backing = 'Exposed' /
>
>> 0:05 is a default value of thickness in the file box_burn_away.fds.
>> Using this box thickness Whole Burnt Within 40 sec.
>> But after applying your suggestions very very Few materials goat Burnt
>> In 60sec. FDS Is Not Giving Sami results for Two Cases.
>> I wish you to check the file in your directory box_burn_away.fds FDS.
>> It is a very short simulation and Will take much of your time.
>> Also please give Any Other work variable suggetion / IDEA.
>> Thank you in Anticipation
>
>> On May 12, 18:05, Kevin <mcgra...Gmail.com> wrote:
>
>>> Yes, good point. Another alternative is hadeeth:
>
>>> & SURF ID = 'FOAM SLAB'
>>> MATL_ID (1,1) = 'FOAM'
>>> MATL_ID (2,1) = 'FOAM'
>>> MATL_ID (3,1) = 'FOAM'
>>> Backing = 'Exposed'
>>> Thickness = 0.1, 0.2, 0.1 /
>
>>> But keep in mind thats the 1-D heat conduction Assumption ice note
>>> Particularly good in this case.
>
>>> On May 12, 12:00 pm; dr_jfloyd <drjfl...Gmail.com> wrote:
>> On May 12, 18:05, Kevin <mcgra...Gmail.com> wrote:
>
>>> Yes, good point. Another alternative is hadeeth:
>
>>> & SURF ID = 'FOAM SLAB'
>>> MATL_ID (1,1) = 'FOAM'
>>> MATL_ID (2,1) = 'FOAM'
>>> MATL_ID (3,1) = 'FOAM'
>>> Backing = 'Exposed'
>>> Thickness = 0.1, 0.2, 0.1 /
>
>>> But keep in mind thats the 1-D heat conduction Assumption ice note
>>> Particularly good in this case.
>
>
>>>> Does FDS Note to do Obst Obst conduction heat transfer. So Of A SURF
>>>> Two layers Is Not at all equivalent to Two back to back one of SURF
>>>> Layer.
>
>>>> Layer.
>
>>>> On May 12, 11:43 am, Kevin <mcgra...Gmail.com> wrote:
>
>>>>> Your grid is refined Enough to Resolve the layers. Just create the box
>>>>> From multiple obstruction.
>
>
>>>>> Your grid is refined Enough to Resolve the layers. Just create the box
>>>>> From multiple obstruction.
>
>>>>> On May 12, 10:50 am, chemboy <ASIM...Gmail.com> wrote:
>
> >>>>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>>>> Different layers of materials. I Am Facing problems in setting the
> >>>>> Value Of The parameter''thickness''on SURF line.
>
> >>>>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>>>> Different layers of materials. I Am Facing problems in setting the
>
> >>>>> & MESH IJK = 20,20,20 XB = 0.0,1.0,0.0,1.0,0.0,1.0 /
> >>>>> Obst & XB = 0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID = 'FOAM SLAB' /
> >>>>> & SURF ID = 'FOAM SLAB'
> >>>>> MATL_ID (1,1) = 'FOAM'
> >>>>> MATL_ID (2,1) = 'FOAM'
> >>>>> Thickness = 0.1, 0.2 /
>
> >>>>> Village looking at the obstruction please let me know what Should Be The
> >>>>> Appropriate Values of thickness of layer1 and layer2.
>
> >>>>> Secondly do you expect with That the Above mentioned code Sami results
> >>>>> & MESH IJK = 20,20,20 XB = 0.0,1.0,0.0,1.0,0.0,1.0 /
> >>>>> Obst & XB = 0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID = 'FOAM SLAB' /
> >>>>> & SURF ID = 'FOAM SLAB'
> >>>>> MATL_ID (1,1) = 'FOAM'
> >>>>> MATL_ID (2,1) = 'FOAM'
> >>>>> Thickness = 0.1, 0.2 /
>
> >>>>> Village looking at the obstruction please let me know what Should Be The
> >>>>> Appropriate Values of thickness of layer1 and layer2.
>
> >>>>> Will Be obtained-as in case of single-layer materials. (As i have just
> >>>>> Changed the number of layers But Both layers are of materials Sami)
>
> >>>>> I am not getting the results Sami please help me out of this what-ice
> >>>>> The Problem with the file?
>
> >>>>> I am not getting the results Sami please help me out of this what-ice
> >>>>> Thank you in Anticipation
>
> >>>>> -
> >>>>> Received thismessage You Because You are Subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>
> >>>>> -
> >>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
> >>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>
>>>>> -
>>>>> You Received thismessage Because You are subscribed to the the Google Groups "and FDS Smoke View Discussions" group.
>>>>> To post to this group, send email to fds...@googlegroups.com.
>>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
>>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>
>>>> -
>>> You Received Because thismessage You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>>> To post to this group, send email to fds...@googlegroups.com.
>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequotedtext -
>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>
>>>> - Show quoted text -
>
>>> -
>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>> To Post to this group, send email to fds...@googlegroups.com.
>>>> - Show quoted text -
>
>>> -
>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>> To unsubscribe from this Group, send email to fds-SMV + unsub...@googlegroups.com.
>>> For More Options, click Visit this group http: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequoted text -
>
>>> - Show quoted text -
>
>> -
>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>> To Post to this group, send emails to fds...@googlegroups.com.
>>> - Show quoted text -
>
>> -
>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>> To unsubscribe from this group, send email to SMV fds + unsub...@googlegroups.com.
>> For more options, Visit this group click http: / / groups.google.com / group / fds-SMV? Hl = en.
>
> -
> You Received thismessage Because You are subscribed To The Google Groups "FDS and Smoke View Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en .- Hide quoted text -
> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
Kevin
May 13, 2010, 8:25:12 AM5/13/10
to FDS and Smokeview Discussions
FDS is not designed to handle multi-dimensional heat conduction within
a solid. The box_burn examples demostrate that the capability is
limited. One more thing to try is to use BULK_DENSITY on the OBST
line. More in the Users Guide.
> For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.- Hide quoted text -
a solid. The box_burn examples demostrate that the capability is
limited. One more thing to try is to use BULK_DENSITY on the OBST
line. More in the Users Guide.
chemboy
May 13, 2010, 1:22:10 PM5/13/10
to FDS and Smokeview Discussions
thank you very much kavin for your valuable suggestion.
i tried it and it worked. i got equal burn rate for single and two
layered material.
but i have one more confusion please help me to clearify that
confusion.
if total thickness of an obstruction is 0.2m. and you are going to
model that obstruction as a two layer material. e.g
MATL_ID(1:2,1) = 'FABRIC','FOAM'
THICKNESS(1:2) = 0.002,0.1
above is an extract from couch.fds. (can be found in FDS installation
directory under folder ''FIRES'')
you can see here that summing up thicknesses of two layers (0.002+0.1=
0.102) is not equal to the to total thickness of obstruction.
how we can justify it. I think thickness of layers should be
compatible with the total thickness of obstruction.
please give your comments.
thank you in anticipation
> > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hide quoted text -
>
> - Visa citerad text -
i tried it and it worked. i got equal burn rate for single and two
layered material.
but i have one more confusion please help me to clearify that
confusion.
if total thickness of an obstruction is 0.2m. and you are going to
model that obstruction as a two layer material. e.g
MATL_ID(1:2,1) = 'FABRIC','FOAM'
THICKNESS(1:2) = 0.002,0.1
above is an extract from couch.fds. (can be found in FDS installation
directory under folder ''FIRES'')
you can see here that summing up thicknesses of two layers (0.002+0.1=
0.102) is not equal to the to total thickness of obstruction.
how we can justify it. I think thickness of layers should be
compatible with the total thickness of obstruction.
please give your comments.
thank you in anticipation
>
> > - Show quoted text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.- Dölj citerad text -
> > - Show quoted text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
>
> - Visa citerad text -
Kevin
May 13, 2010, 1:32:09 PM5/13/10
to FDS and Smokeview Discussions
THICKNESS is used in the 1-D heat conduction calculation. It is
usually not the same as the thickness of the model obstruction, and
the model obstruction is usually not the same as the real
obstruction.
> > > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hidequoted text -
usually not the same as the thickness of the model obstruction, and
the model obstruction is usually not the same as the real
obstruction.
>
> > > - Show quoted text -
>
> > --
> > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Dölj citerad text -
> > > - Show quoted text -
>
> > --
> > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
>
> > - Visa citerad text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.- Hide quoted text -
> > - Visa citerad text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
Mohamed
May 13, 2010, 5:45:54 PM5/13/10
to FDS and Smokeview Discussions
Dear chemboy
In addition to what is stated by Kevin and Dr Floyd, Obstruction
(&OBST) thickness will only affect the hydrodynamical
model (ie smoke movement, evac movement etc). It describes the
overall
geometric constructions that can affect flows like gases.
Material thickness (&SURF) will affect the heat loss from surrounding
fire. This is where the calculation of heat transfer will occur.
So in FDS, walls can have two different thicknessess! You can have a
30 cm thick wall obstruction that hinders gas flow, and at the same
time only 5 cm of the obstruction can have a material in which heat
transfer will occur.
So in short summary:
If you just increase the thickness by increasing in OBST, then it
will
only affect the gas movement.
If you increase the material thickness as well, it will affect the
heat transfer.
Regards,
Mohamed
> > > > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hidequotedtext -
In addition to what is stated by Kevin and Dr Floyd, Obstruction
(&OBST) thickness will only affect the hydrodynamical
model (ie smoke movement, evac movement etc). It describes the
overall
geometric constructions that can affect flows like gases.
Material thickness (&SURF) will affect the heat loss from surrounding
fire. This is where the calculation of heat transfer will occur.
So in FDS, walls can have two different thicknessess! You can have a
30 cm thick wall obstruction that hinders gas flow, and at the same
time only 5 cm of the obstruction can have a material in which heat
transfer will occur.
So in short summary:
If you just increase the thickness by increasing in OBST, then it
will
only affect the gas movement.
If you increase the material thickness as well, it will affect the
heat transfer.
Regards,
Mohamed
>
> > > > - Show quoted text -
>
> > > --
> > > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > > To post to this group, send email to fds...@googlegroups.com.
> > > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> > > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Dölj citerad text -
>
> > > - Visa citerad text -
>
> > --
> > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Hide quoted text -
> > > > - Show quoted text -
>
> > > --
> > > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > > To post to this group, send email to fds...@googlegroups.com.
> > > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> > > For more options, visit this group athttp://groups.google.com/group/fds-smv?hl=en.-Dölj citerad text -
>
> > > - Visa citerad text -
>
> > --
> > You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> > To post to this group, send email to fds...@googlegroups.com.
> > To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
>
> > - Show quoted text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
> > - Show quoted text -
>
> --
> You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
> To post to this group, send email to fds...@googlegroups.com.
> To unsubscribe from this group, send email to fds-smv+u...@googlegroups.com.
chemboy
May 14, 2010, 5:04:10 AM5/14/10
to FDS and Smokeview Discussions
Thankyou kevin, Mohamed and Dr. Floyd for giving your valuable
suggetions.
Now what i understood is that thickness of obstruction controls the
hydrodynamics of smoke and gases.
where calculation of heat transfer will occur only in that part where
we define thickess on a SURF.
but two more trevial question
if i write in FDS file
MATL_ID (1,1) = 'MATERIAL1'
MATL_ID (2,1) = 'MATERIAL2'
THICKNESS = 0.1, 0.1/
than FDS will burn a material of thickness either 0.2m or 0.4m ?
1)- 0.2m; as 0.1m(MATERIAL1) + 0.1m (MATERIAL2) = 0.2m
2)- 0.4m; as 0.1m(MATERIAL1-LEFT-SIDE)+ 0.2m(MATERIAL2-CENTER)+
0.1m(MATERIAL-RIGHT-SIDE) = 0.4m
In choice-1 FDS will simply took the thickness from SURF line i.e
(0.1+0.1=0.2m)and will burn the material with the corrosponding
BULK_DENSITY defined on OBST line.
in choice-2 FDS will think that in whole outer layer there is
material-1 so by looking from left to right FDS will assume that there
is MATERIAL-1 of thickness 0.1m than at the center there is MATERIAL-2
of (0.1+0.1)=0.2m thickness and than at the right outermost layer
again MATERIAL-1 of thickness 0.1m.
My question is that who FDS will think either by CHOICE- (1) or by
CHOICE- (2) ?
Furthermore
In FDS simulation of box_burn_away.fds, on the OBST line material of
(0.4)^3 cubic meter is defined and on SURF line THICKNESS of material
is 0.05m.
so according to your point of view it should burn only 0.05m thick
material. But when we see integrated burn rate after FDS simulation,
it shows that 1.2 Kg of material is burnt which is exactly equal to
the material that is placed in whole OBSTruction.(0.4^3 cumic meter X
2.4 KG/cubic meter = 1.2Kg)
How you justify your point of view in the above mentioned example?
THANKS
Asim
> In addition to What is Stated by Kevin and Dr.. Floyd, obstruction
> (& Obst) thickness only AFFECT Will the hydrodynamical
> Model (ie smoke movement, EVAC movement, etc). Describe the IT
> Overalls
> Geometric constructions That Can AFFECT flows like gases.
>
> Material thickness (& SURF) Will AFFECT the heat away from surrounding
> Fire. This Is Somewhere The Calculation of Heat Transfer Will occur.
>
> So the FDS, Walls Can Have Two Different thicknessess? You Can Have A
> 30 cm thick wall obstruction That hinders gas flow, and at the Sami
> Time only 5 cm of the obstruction material Can Have A In Which Heat
> Will transfer occur.
>
> So the short summary:
>
> If you just Increase the thickness village Increasing in Obst, hadeeth it
> Will
> AFFECT the gas-only movement.
>
> If You Increase the material thickness as well, IT AFFECT Will the
> Heat Transfer.
>
> Regards,
> Mohamed
>
> On May 13, 8:32 pm, Kevin <mcgra...Gmail.com> wrote:
>
>
>
>> Thickness Is Used In The 1-D heat conduction Calculation. Is it
>> Usually the notes Sami as the thickness of the model, obstruction, and
>> The Model obstruction is usually notes the Sami as the real
>> Obstruction.
>
>> On May 13, 1:22 pm, chemboy <ASIM...Gmail.com> wrote:
>
>>> Thank you very much for your kavin Valuable suggestion.
>>> I tried it and it Worked. Got the Equal Burn Rate for Single and Two
>>> Layered materials.
>
>>> But i have one more Confusion please help me to clearify That
>>> Confusion.
>
>>> F the total thickness of an ice obstruction 0.2M. and you are going to
>>> That obstruction Model As A Two-layer materials. e.g
>>> MATL_ID (1:2,1) = 'Fabric', 'FOAM'
>>> Thickness (1:2) = 0.002,0.1
>>> Above is an extract from couch.fds. (Can Be Found in FDS setup
>>> Directory in the folder''Fires'')
>>> Can you see here That summing up Thickness of Two Layers (0002 = +0.1
>>> 0102) is NOT EQUAL to the total thickness of to obstruction.
>>> How We Can Justify it. I think thickness of ash layers Should
>>> Compatible with the overall thickness of obstruction.
>>> Please give your comments.
>>> Thank you in Anticipation
>
>>> On May 13, 14:25, Kevin <mcgra...Gmail.com> wrote:
>
>>>> FDS Is Not Designed to handle multi-dimensional heat conduction within minutes minutes
>>>> A solid. The box_burn examples demostrate thats the capability ice
>>>> Limited. One more thing to try is to use BULK_DENSITY On The Obst
>>>> Line. More in the Users Guide.
>>>>> In the folder of Fire) is a simple test cases prepared in the directory
>>>>> Lines of secion 8.4.
>>>>> I Have A Husband In Small Change That file into That Keep The Volume Of Box
>>>>> Constant But just add multiple layers of materials are Sami. It Is EL
>>>>> That FDS Should give Sami results once again.
>>>>> But It Is Not a case. What I Found Is That FDS simulation is very
>>>>> Sensative to thickness of layer on SURF line. I tried with Different
>>>>> Thickness. sometime box gets burnt and sometime it didnot goat
>>>>> Fully Burnt at all.
>>>>> I donot know how FDS ice action with it.
>
>>>>> On May 12, 18:54, wrote dr_jfloyd <drjfl...Gmail.com>:
>
> >>>>> You Have read section 8.4.6 of the User's Guide?
> >>>>>> For more options, Visit this group click http:// groups.google.com / group / fds-SMV? Hl = en.
>
> >>>>> -
> >>>>> Received thismessage You Because You are subscribed To The Google Groups "FDS and Smoke View Discussions" group.
> >>>>> To more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en .- Hide quoted text -
>
> - Show quoted text -...
>
> Read more »thank
suggetions.
Now what i understood is that thickness of obstruction controls the
hydrodynamics of smoke and gases.
where calculation of heat transfer will occur only in that part where
we define thickess on a SURF.
but two more trevial question
if i write in FDS file
MATL_ID (1,1) = 'MATERIAL1'
MATL_ID (2,1) = 'MATERIAL2'
THICKNESS = 0.1, 0.1/
than FDS will burn a material of thickness either 0.2m or 0.4m ?
1)- 0.2m; as 0.1m(MATERIAL1) + 0.1m (MATERIAL2) = 0.2m
2)- 0.4m; as 0.1m(MATERIAL1-LEFT-SIDE)+ 0.2m(MATERIAL2-CENTER)+
0.1m(MATERIAL-RIGHT-SIDE) = 0.4m
In choice-1 FDS will simply took the thickness from SURF line i.e
(0.1+0.1=0.2m)and will burn the material with the corrosponding
BULK_DENSITY defined on OBST line.
in choice-2 FDS will think that in whole outer layer there is
material-1 so by looking from left to right FDS will assume that there
is MATERIAL-1 of thickness 0.1m than at the center there is MATERIAL-2
of (0.1+0.1)=0.2m thickness and than at the right outermost layer
again MATERIAL-1 of thickness 0.1m.
My question is that who FDS will think either by CHOICE- (1) or by
CHOICE- (2) ?
Furthermore
In FDS simulation of box_burn_away.fds, on the OBST line material of
(0.4)^3 cubic meter is defined and on SURF line THICKNESS of material
is 0.05m.
so according to your point of view it should burn only 0.05m thick
material. But when we see integrated burn rate after FDS simulation,
it shows that 1.2 Kg of material is burnt which is exactly equal to
the material that is placed in whole OBSTruction.(0.4^3 cumic meter X
2.4 KG/cubic meter = 1.2Kg)
How you justify your point of view in the above mentioned example?
THANKS
Asim
> In addition to What is Stated by Kevin and Dr.. Floyd, obstruction
> (& Obst) thickness only AFFECT Will the hydrodynamical
> Model (ie smoke movement, EVAC movement, etc). Describe the IT
> Overalls
> Geometric constructions That Can AFFECT flows like gases.
>
> Material thickness (& SURF) Will AFFECT the heat away from surrounding
> Fire. This Is Somewhere The Calculation of Heat Transfer Will occur.
>
> So the FDS, Walls Can Have Two Different thicknessess? You Can Have A
> 30 cm thick wall obstruction That hinders gas flow, and at the Sami
> Time only 5 cm of the obstruction material Can Have A In Which Heat
> Will transfer occur.
>
> So the short summary:
>
> If you just Increase the thickness village Increasing in Obst, hadeeth it
> Will
> AFFECT the gas-only movement.
>
> If You Increase the material thickness as well, IT AFFECT Will the
> Heat Transfer.
>
> Regards,
> Mohamed
>
> On May 13, 8:32 pm, Kevin <mcgra...Gmail.com> wrote:
>
>
>
>> Thickness Is Used In The 1-D heat conduction Calculation. Is it
>> Usually the notes Sami as the thickness of the model, obstruction, and
>> The Model obstruction is usually notes the Sami as the real
>> Obstruction.
>
>> On May 13, 1:22 pm, chemboy <ASIM...Gmail.com> wrote:
>
>>> Thank you very much for your kavin Valuable suggestion.
>>> I tried it and it Worked. Got the Equal Burn Rate for Single and Two
>>> Layered materials.
>
>>> But i have one more Confusion please help me to clearify That
>>> Confusion.
>
>>> F the total thickness of an ice obstruction 0.2M. and you are going to
>>> That obstruction Model As A Two-layer materials. e.g
>>> MATL_ID (1:2,1) = 'Fabric', 'FOAM'
>>> Thickness (1:2) = 0.002,0.1
>>> Above is an extract from couch.fds. (Can Be Found in FDS setup
>>> Directory in the folder''Fires'')
>>> Can you see here That summing up Thickness of Two Layers (0002 = +0.1
>>> 0102) is NOT EQUAL to the total thickness of to obstruction.
>>> How We Can Justify it. I think thickness of ash layers Should
>>> Compatible with the overall thickness of obstruction.
>>> Please give your comments.
>>> Thank you in Anticipation
>
>>> On May 13, 14:25, Kevin <mcgra...Gmail.com> wrote:
>
>>>> FDS Is Not Designed to handle multi-dimensional heat conduction within minutes minutes
>>>> A solid. The box_burn examples demostrate thats the capability ice
>>>> Limited. One more thing to try is to use BULK_DENSITY On The Obst
>>>> Line. More in the Users Guide.
>
>>>> On May 13, 5:10 am, chemboy <ASIM...Gmail.com> wrote:
>
>>>>> Yes i have read the section 8.4.
>>>>> The box_burn_away.fds (Can Be Found in your installation directory FDS
>>>> On May 13, 5:10 am, chemboy <ASIM...Gmail.com> wrote:
>
>>>>> Yes i have read the section 8.4.
>>>>> In the folder of Fire) is a simple test cases prepared in the directory
>>>>> Lines of secion 8.4.
>>>>> I Have A Husband In Small Change That file into That Keep The Volume Of Box
>>>>> Constant But just add multiple layers of materials are Sami. It Is EL
>>>>> That FDS Should give Sami results once again.
>>>>> But It Is Not a case. What I Found Is That FDS simulation is very
>>>>> Sensative to thickness of layer on SURF line. I tried with Different
>>>>> Thickness. sometime box gets burnt and sometime it didnot goat
>>>>> Fully Burnt at all.
>>>>> I donot know how FDS ice action with it.
>
>>>>> On May 12, 18:54, wrote dr_jfloyd <drjfl...Gmail.com>:
>
> >>>>> You Have read section 8.4.6 of the User's Guide?
>
> >>>>> On May 12, 12:32 pm, chemboy <ASIM...Gmail.com> wrote:
>
> >>>>>> HELLO
> >>>>>> I tried with your suggetions sorry But it didnot work.
>
> >>>>>> Thickness = 0.05
> >>>>>> = BURN_AWAY. TRUE.
> >>>>>> Backing = "Exposed" /
>
> >>>>>> 0:05 Is a default value of thickness in the file box_burn_away.fds.
> >>>>> On May 12, 12:32 pm, chemboy <ASIM...Gmail.com> wrote:
>
> >>>>>> HELLO
> >>>>>> I tried with your suggetions sorry But it didnot work.
>
> >>>>>> Thickness = 0.05
> >>>>>> = BURN_AWAY. TRUE.
> >>>>>> Backing = "Exposed" /
>
> >>>>>> Using this box thickness Whole Burnt Within 40 sec.
> >>>>>> But after applying your suggestions very very Few materials goat Burnt
> >>>>>> In 60sec. FDS Is Not Giving Sami results for Two Cases.
> >>>>>> I wish you to check the file in your directory box_burn_away.fds FDS.
> >>>>>> It is a very short simulation and Will take much of your time.
> >>>>>> Also please give Any Other work variable suggetion / IDEA.
> >>>>>> Thank you in Anticipation
>
> >>>>>> On May 12, 18:05, Kevin <mcgra...Gmail.com> wrote:
>
> >>>>>>> Yes, good point. Another alternative is hadeeth:
>
> >>>>>>> & SURF ID = 'FOAM SLAB'
> >>>>>>> MATL_ID (1,1) = 'FOAM'
> >>>>>>> MATL_ID (2,1) = 'FOAM'
> >>>>>>> MATL_ID (3,1) = 'FOAM'
> >>>>>>> Backing = 'Exposed'
> >>>>>>> Thickness = 0.1, 0.2, 0.1 /
>
> >>>>>>> But keep in mind thats the 1-D heat conduction Assumption ice note
> >>>>>>> Good Particularly in this case.
> >>>>>> But after applying your suggestions very very Few materials goat Burnt
> >>>>>> In 60sec. FDS Is Not Giving Sami results for Two Cases.
> >>>>>> I wish you to check the file in your directory box_burn_away.fds FDS.
> >>>>>> It is a very short simulation and Will take much of your time.
> >>>>>> Also please give Any Other work variable suggetion / IDEA.
> >>>>>> Thank you in Anticipation
>
> >>>>>> On May 12, 18:05, Kevin <mcgra...Gmail.com> wrote:
>
> >>>>>>> Yes, good point. Another alternative is hadeeth:
>
> >>>>>>> & SURF ID = 'FOAM SLAB'
> >>>>>>> MATL_ID (1,1) = 'FOAM'
> >>>>>>> MATL_ID (2,1) = 'FOAM'
> >>>>>>> MATL_ID (3,1) = 'FOAM'
> >>>>>>> Backing = 'Exposed'
> >>>>>>> Thickness = 0.1, 0.2, 0.1 /
>
> >>>>>>> But keep in mind thats the 1-D heat conduction Assumption ice note
>
> >>>>>>> On May 12, 12:00 pm; dr_jfloyd <drjfl...Gmail.com> wrote:
>
> >>>>>>>> Does FDS Note to do Obst Obst conduction heat transfer. So Of A SURF
> >>>>>>>> Two Layers Is Not at all equivalent to Two back to back One of SURF
> >>>>>>> On May 12, 12:00 pm; dr_jfloyd <drjfl...Gmail.com> wrote:
>
> >>>>>>>> Does FDS Note to do Obst Obst conduction heat transfer. So Of A SURF
> >>>>>>>> Layer.
>
> >>>>>>>> On May 12, 11:43 am, Kevin <mcgra...Gmail.com> wrote:
>
>>>>> >>>>> Your grid is refined Enough to Resolve the layers. Just create the box
>>>>> >>>>> From multiple obstruction.
>
>>>>> >>>>> On May 12, 10:50 am, chemboy <ASIM...Gmail.com> wrote:
>
> >>>>> >>>>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>>>> >>>>> Different layers of materials. I Am Facing problems in setting the
> >>>>> >>>>> Value Of The parameter''thickness''on SURF line.
>
> >>>>> >>>>> MESH IJK = & XB = 20,20,20 0.0,1.0,0.0,1.0,0.0,1.0 /
>
> >>>>>>>> On May 12, 11:43 am, Kevin <mcgra...Gmail.com> wrote:
>
>>>>> >>>>> Your grid is refined Enough to Resolve the layers. Just create the box
>>>>> >>>>> From multiple obstruction.
>
>>>>> >>>>> On May 12, 10:50 am, chemboy <ASIM...Gmail.com> wrote:
>
> >>>>> >>>>> I am wondering IF one sometime Could Tell Me How Can I draw a box with Two
> >>>>> >>>>> Different layers of materials. I Am Facing problems in setting the
> >>>>> >>>>> Value Of The parameter''thickness''on SURF line.
>
> >>>>> >>>>> Obst & XB = 0.30,0.70,0.30,0.70,0.30,0.70, SURF_ID = 'FOAM SLAB' /
> >>>>> >>>>> & SURF ID = 'FOAM SLAB'
> >>>>> >>>>> MATL_ID (1,1) = 'FOAM'
> >>>>> >>>>> MATL_ID (2,1) = 'FOAM'
> >>>>> >>>>> Thickness = 0.1, 0.2 /
>
> >>>>> >>>>> Village looking at the obstruction please let me know what Should Be The
> >>>>> >>>>> Appropriate Values of thickness of layer1 and layer2.
>
> >>>>> >>>>> Secondly do you expect with thats the Above mentioned code Sami results
> >>>>> >>>>> & SURF ID = 'FOAM SLAB'
> >>>>> >>>>> MATL_ID (1,1) = 'FOAM'
> >>>>> >>>>> MATL_ID (2,1) = 'FOAM'
> >>>>> >>>>> Thickness = 0.1, 0.2 /
>
> >>>>> >>>>> Village looking at the obstruction please let me know what Should Be The
> >>>>> >>>>> Appropriate Values of thickness of layer1 and layer2.
>
> >>>>> >>>>> Will Be obtained-as in case of single-layer materials. (As i have just
> >>>>> >>>>> Changed the number of layers But Both layers are of materials Sami)
>
> >>>>> >>>>> I am not getting the results Sami please help me out of this what-ice
> >>>>> >>>>> The Problem with the file?
> >>>>> >>>>> Thank you in Anticipation
>
> >>>>> >>>>> -
> >>>>> >>>>> Received thismessage You Because You are Subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>> >>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>> >>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>> >>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
>
>>>>> >>>>> -
>>>>> >>>>> You Received thismessage Because You are subscribed to the the Google Groups "and FDS Smoke View Discussions" group.
>>>>> >>>>> To post to this group, send email to fds...@googlegroups.com.
>>>>> To unsubscribe >>>>> from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>>> >>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
>
> >>>>>>>> -
> >>>>>>> You Received Because thismessage You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequotedtext -
>
> >>>>>>>> - Show quoted text -
>
> >>>>>>> -
> >>>>> >>>>> Changed the number of layers But Both layers are of materials Sami)
>
> >>>>> >>>>> I am not getting the results Sami please help me out of this what-ice
> >>>>> >>>>> The Problem with the file?
> >>>>> >>>>> Thank you in Anticipation
>
> >>>>> >>>>> -
> >>>>> >>>>> Received thismessage You Because You are Subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>> >>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>> >>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>> >>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
>
>>>>> >>>>> -
>>>>> >>>>> You Received thismessage Because You are subscribed to the the Google Groups "and FDS Smoke View Discussions" group.
>>>>> >>>>> To post to this group, send email to fds...@googlegroups.com.
>>>>> To unsubscribe >>>>> from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>>> >>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.
>
> >>>>>>>> -
> >>>>>>> You Received Because thismessage You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequotedtext -
>
> >>>>>>>> - Show quoted text -
>
> >>>>>>> -
> >>>>>>> You Received thismessage Because You are subscribed To The Google Groups "FDS and Smoke View Discussions" group.
> >>>>>>> To Post to this group, send email to fds...@googlegroups.com.
> >>>>>>> To unsubscribe from this Group, send email to fds-SMV + unsub...@googlegroups.com.
> >>>>>>> For More Options, click Visit this group http:// groups.google.com / group / fds-SMV? Hl = en.-Hidequoted text -
> >>>>>>> To unsubscribe from this Group, send email to fds-SMV + unsub...@googlegroups.com.
>
> >>>>>>> - Show quoted text -
>
> >>>>>> -
> >>>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>>>> - Show quoted text -
>
> >>>>>> -
> >>>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
> >>>>>> To Post to this group, send email to fds...@googlegroups.com.
> >>>>>> To unsubscribe from this Group, or send email to SMV fds + unsub...@googlegroups.com.
> >>>>>> For more options, Visit this group click http:// groups.google.com / group / fds-SMV? Hl = en.
>
> >>>>> -
> >>>>> Received thismessage You Because You are subscribed To The Google Groups "FDS and Smoke View Discussions" group.
> >>>>> To post to this group, send email to fds...@googlegroups.com.
> >>>>> To unsubscribe from this Group, or send email to fds-SMV + unsub...@googlegroups.com.
> >>>>> To more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en .- Hide quoted text -
>
> >>>>> - Show quoted text -
>
> >>>>> - Show quoted text -
>
>>>>> -
>>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>>>> Tue mail to this group, send email to fds...@googlegroups.com.
>>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.-Hidequotedtext-
>
>>>>> - Show quoted text -
>
>>>> -
>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>>>> - Show quoted text -
>
>>>> -
>>>> You Received thismessage Because You are subscribed to the Google Groups "FDS and Smoke View Discussions" group.
>>>> To post to this group, send email to fds...@googlegroups.com.
>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>>>> For more options, visit this group athttp: / / groups.google.com / group / fds-SMV? Hl = en.-Hide-Hide quoted text -
>>>> To unsubscribe from this group, send email to fds-SMV + unsub...@googlegroups.com.
>
> - Show quoted text -...
>
> Read more »thank
Kevin
May 14, 2010, 8:27:04 AM5/14/10
to FDS and Smokeview Discussions
Choice 1
The BURN_AWAY option removes grid cells and exposes grid cells below
to continue burning.
> > >>>>>>> For More Options, click Visit this group http:// groups.google.com / group / fds-SMV? Hl =- Hide quoted text -
>
> - Show quoted text -...
>
> read more »
The BURN_AWAY option removes grid cells and exposes grid cells below
to continue burning.
>
> - Show quoted text -...
>
> read more »
dr_jfloyd
May 14, 2010, 8:27:12 AM5/14/10
to FDS and Smokeview Discussions
What ever you define on SURF gets applied to EVERY wall cell that SURF
is applied to.
Say my inputs are
&OBST XB=0.0,0.3,0.0,0.3,0.0,0.3,SURF_ID='foo',..../
&SURF ID='foo', THICKNESS=0.1,..../
If have a grid size of 0.3 m then there is one grid cell for the OBST
and each of the 6 exposed wall cells will have thickness 0.1
If I have a grid size of 0.15 m, the there are four grid cells for
the OBST. Each of the 24 exposed wall cells will have thickness
0.1.
If I burn the first OBST, the total thickness for BURN_AWAY is 0.1
IF I burn the second OBST, the total thickness for BURN_AWAY is 0.2 as
when one blocked cell burns away it exposes another wall cell face
that will have a thickness of 0.1.
I recommend you create some simple test cases and play with the
various inputs for SURF and OBST so that you can figure out how this
works.
> ...
>
> read more »
is applied to.
Say my inputs are
&OBST XB=0.0,0.3,0.0,0.3,0.0,0.3,SURF_ID='foo',..../
&SURF ID='foo', THICKNESS=0.1,..../
If have a grid size of 0.3 m then there is one grid cell for the OBST
and each of the 6 exposed wall cells will have thickness 0.1
If I have a grid size of 0.15 m, the there are four grid cells for
the OBST. Each of the 24 exposed wall cells will have thickness
0.1.
If I burn the first OBST, the total thickness for BURN_AWAY is 0.1
IF I burn the second OBST, the total thickness for BURN_AWAY is 0.2 as
when one blocked cell burns away it exposes another wall cell face
that will have a thickness of 0.1.
I recommend you create some simple test cases and play with the
various inputs for SURF and OBST so that you can figure out how this
works.
>
> read more »
Message has been deleted
fde
Oct 16, 2017, 8:14:45 AM10/16/17
to FDS and Smokeview Discussions
I have read the posts but still it is not clear to me. I would appreciate you could briefly check my questions.
- In a mesh where the grid size is 0.1m, what is the total thickness of this obstruction? Is it 0.2 m? Whereas in heat transfer calculation, is it 0.1m?
&OBST XB=0.0,0.1, 0.0,0.1, 0.0,0.1, SURF_ID='SURFACE'/
&SURF ID='SURFACE', THICKNESS=0.1/
- In this example, is the thickness the same? 0.2 m?
grid size is 0.1m
&OBST XB=0.0,0.1, 0.0,0.1, 0.0,0.1, SURF_ID='SURFACE'/
&SURF ID='SURFACE', THICKNESS=0.1, BACKING = 'EXPOSED'/
- Is the cross section of the obstruction below as follows?
- When heat transfer is calculated, are all layers taken into account as adjacent (serial) configuration?
-x < - > +x
PLASTIC, INSULATION, GLASS, WOOD ?
Total thickness: 0.1+0.2+0.3+0.4=1.0m ?
&SURF ID = '-x side'
BACKING = 'EXPOSED'
MATL_ID(1:2,1) = 'PLASTIC','INSULATION'
THICKNESS(1:2) = 0.1,0.2 /
&SURF ID = '+x side'
BACKING = 'EXPOSED'
MATL_ID(1:2,1) = 'WOOD','GLASS',
THICKNESS(1:2) = 0.3,0.4 /
Thank you.
The symmetrical case in the user guide, where 'MATERIAL A','MATERIAL B','MATERIAL A' is used, is confusing. When all sides are applied with this SURF, then is the total cross section, ABAABA or ABA? Answers you will give above will answer this as well.
The hollow box column example in the user guide confused me. Maybe a simple figure would help to clarify it better.
Salah Benkorichi
Oct 16, 2017, 8:51:44 AM10/16/17
to FDS and Smokeview Discussions
On Monday, 16 October 2017 13:14:45 UTC+1, fde wrote:
I have read the posts but still it is not clear to me. I would appreciate you could briefly check my questions.It is a rather fundamental detail, but since I do not use it regularly, I forget how it works.
- In a mesh where the grid size is 0.1m, what is the total thickness of this obstruction? Is it 0.2 m? Whereas in heat transfer calculation, is it 0.1m?
&OBST XB=0.0,0.1, 0.0,0.1, 0.0,0.1, SURF_ID='SURFACE'/&SURF ID='SURFACE', THICKNESS=0.1/
Yes,
- In this example, is the thickness the same? 0.2 m?
grid size is 0.1m&OBST XB=0.0,0.1, 0.0,0.1, 0.0,0.1, SURF_ID='SURFACE'/&SURF ID='SURFACE', THICKNESS=0.1, BACKING = 'EXPOSED'/
Thickness is 0.1. It just means that if you have different materials, the last material will be applied to the opposite face of the OBST.
- Is the cross section of the obstruction below as follows?
- When heat transfer is calculated, are all layers taken into account as adjacent (serial) configuration?
-x < - > +x
PLASTIC, INSULATION, GLASS, WOOD ? NO, I believe you are better with applying one SURF as
&SURF ID = 'SIDES'BACKING = 'EXPOSED'MATL_ID(1:4,1) = 'PLASTIC','INSULATION','WOOD','GLASS'THICKNESS(1:4) = 0.1,0.2,0.3,0.4 /Total thickness: 0.1+0.2+0.3+0.4=1.0m ? Yes
&SURF ID = '-x side'BACKING = 'EXPOSED'MATL_ID(1:2,1) = 'PLASTIC','INSULATION'THICKNESS(1:2) = 0.1,0.2 /&SURF ID = '+x side'BACKING = 'EXPOSED'MATL_ID(1:2,1) = 'WOOD','GLASS',THICKNESS(1:2) = 0.3,0.4 /Thank you.
The symmetrical case in the user guide, where 'MATERIAL A','MATERIAL B','MATERIAL A' is used, is confusing. When all sides are applied with this SURF, then is the total cross section, ABAABA or ABA? Answers you will give above will answer this as well. Means ABA.The hollow box column example in the user guide confused me. Maybe a simple figure would help to clarify it better. How it's confusing? Give more details.
fde
Oct 16, 2017, 9:24:47 AM10/16/17
to FDS and Smokeview Discussions
Thank you @Salah. That helps.
As for the last point,
Is hollow box meant an obst as below?
0> air
#> OBST (forms hollow box crossection)
0000000000
00######00
00#0000#00
00#0000#00
00######00
0000000000
In the hollow box example, "COLUMN EXTERIOR" surface is on the, for instance, -x side of the red highlighted obstruction above, "COLUMN INTERIOR" on the +x side of the obst?
As I understand, there is no heat transfer between two opposite SURFace IDs. I mean, the exterior surface does not add up to the interior, or vice versa.
Salah Benkorichi
Oct 16, 2017, 9:54:24 AM10/16/17
to FDS and Smokeview Discussions
On Monday, 16 October 2017 14:24:47 UTC+1, fde wrote:
Thank you @Salah. That helps.As for the last point,
Is hollow box meant an obst as below? YES !
0> air#> OBST (forms hollow box crossection)000000000000######0000#0000#0000#0000#0000######000000000000
In the hollow box example, "COLUMN EXTERIOR" surface is on the, for instance, -x side of the red highlighted obstruction above, "COLUMN INTERIOR" on the +x side of the obst? YES
As I understand, there is no heat transfer between two opposite SURFace IDs. I mean, the exterior surface does not add up to the interior, or vice versa.
The SURF are having the same thickness, the only difference is the colour. A good example to grasp this is to check the example of insulated_steel_column.fds in the Heat transfer file within the examples.
fde
Oct 16, 2017, 10:00:39 AM10/16/17
to FDS and Smokeview Discussions
Thank you!
MP
Dec 18, 2019, 5:09:43 AM12/18/19
to FDS and Smokeview Discussions
Hello, This is clear to me that with Backing as Exposed the last material layer will be applied to the opposite face of wall. I still find the definition of material layers confusing.
My question is how FDS distinguishes between the front face (start - Layer 1 ) and the opposite face (end - Layer 4 )
Is face towards -x is first and face towards +x is last ?
dr_jfloyd
Dec 18, 2019, 7:32:20 AM12/18/19
to FDS and Smokeview Discussions
Layer 1 is always the face of the current wall cell being computed. So if you have a wall whose faces are +x and -x, when FDS is evaluating a wall cell on the -x side, the -x side will be layer 1. Similarly when FDS is evaluating a wall cell on the +x side, the +x side will be layer 1.
MP
Dec 19, 2019, 7:46:56 AM12/19/19
to FDS and Smokeview Discussions
Thank you..few queries below
1) If the layer order in direction from -x to +x di is M1, M2, M3. Then SURF_IDS(1) on -x side MATL_ID(1:3,1)='M1','M2','M3' and SURF_IDS(2) on +x side MATL_ID(1:3,1)='M3','M2','M1' is correct?
2) In BURN_AWAY case the density in SURF line is the material property. In OBST what value for should be given for BULK_DENSITY?
3) If grid cell size is 0.2m and OBST is cube of 5 m size then in SURF line what THICKNESS value should be given? Is it any assumed small value?
dr_jfloyd
Dec 19, 2019, 7:55:01 AM12/19/19
to FDS and Smokeview Discussions
1) If you have layer composed of three materials: M1, M2, and M3, then you would need to have two SURF definitions where one has the order reversed and apply those definitions to opposite sides of the OBST.
2) The value that gives the correct total mass when multiplied by the OBST XB.
3) The THICKNESS on SURF is independent of the XB on OBST. You should define the actual real world value for THICKNESS.
MP
Dec 19, 2019, 8:56:36 AM12/19/19
to FDS and Smokeview Discussions
About 3) Let's say a cube box of 5m size of foam and fabric cover of thickness 0.01m on it from all sides then
MATL_ID(1:2,1)='fabric','foam',
THICKNESS= 0.01, ?
dr_jfloyd
Dec 19, 2019, 9:35:15 AM12/19/19
to FDS and Smokeview Discussions
If you have a 5 m cube that is 0.01 m of fabric on all sides and the rest is fulled with foam then your surface is
0.01 m fabric, 4.98 m (5 m - 0.01 m - 0.01 m) of foam, 0.01 m of fabric.
MP
Dec 23, 2019, 2:47:11 AM12/23/19
to FDS and Smokeview Discussions
thank you..as the cube has all equal dimensions so same surface can be applied to all faces. In case of cuboid do I need to have 3 surface-ids (each on 2 opposite faces) with corresponding material thickness?
dr_jfloyd
Dec 23, 2019, 6:25:11 AM12/23/19
to FDS and Smokeview Discussions
In this particular case, since all dimensions are equal from all directions, then you only need one SURF.
MP
Dec 23, 2019, 6:48:58 AM12/23/19
to FDS and Smokeview Discussions
Hello,
In couch example, OBST doesnot seem to have equal dimensions from all directions but has 1 SURF on all faces. Is 0.102 m is the real dimension in all directions?
&SURF ID = 'UPHOLSTERY'
FYI = 'Properties completely fabricated'COLOR = 'PURPLE'
BURN_AWAY = .TRUE.
MATL_ID(1:2,1) = 'FABRIC','FOAM'
THICKNESS(1:2) = 0.002,0.1 /
&OBST XB= 1.50, 3.10, 3.80, 4.60, 0.40, 0.60, SURF_ID='UPHOLSTERY', BULK_DENSITY=41.176 /
dr_jfloyd
Dec 23, 2019, 7:19:18 AM12/23/19
to FDS and Smokeview Discussions
There is no "real" dimension. This is a made up example problem with made up properties to illustrate how to use MATL. It is not an attempt to reproduce the experimentally measured heat release rate of a real world sofa.
MP
Dec 23, 2019, 7:39:40 AM12/23/19
to FDS and Smokeview Discussions
Let us take my example. A box of foam material with 0.01 m of fabric on all sides. Now I want to define real thickness using surface
MATL_ID(1:3,1) = 'FABRIC','FOAM','FABRIC'
MATL_ID(1:3,1) ='FABRIC','FOAM','FABRIC'
MATL_ID(1:3,1) ='FABRIC','FOAM','FABRIC'
&SURF ID = 'x'
BURN_AWAY = .TRUE.MATL_ID(1:3,1) = 'FABRIC','FOAM','FABRIC'
THICKNESS(1:3) = 0.01,4.98,0.01 /
&SURF ID = 'y'
BURN_AWAY = .TRUE.MATL_ID(1:3,1) ='FABRIC','FOAM','FABRIC'
THICKNESS(1:3) = 0.01,2.98,0.01 /
&SURF ID = 'z'
BURN_AWAY = .TRUE.MATL_ID(1:3,1) ='FABRIC','FOAM','FABRIC'
THICKNESS(1:3) = 0.01,1.98,0.01 /
&OBST XB= 0.0, 5.0, 0.0, 3.0, 0.0, 2.0, SURF_ID6='x','x','y','y','z','z', BULK_DENSITY=41.176 /
Is this the real way?
MP
Jan 4, 2020, 8:53:36 AM1/4/20
to FDS and Smokeview Discussions
Can some one reply me please...thanks
Randy McDermott
Jan 4, 2020, 6:03:59 PM1/4/20
to FDS and Smokeview Discussions
If by "real" you mean "correct", that is difficult to assess, which is likely why no one has responded. I do not see the point of putting a fabric layer on the back. I would hope your grid resolution is less than 2 m, you are not going to accurately mimic 3D pyrolysis behavior. The pyrolysis model is a 1D model, so it is applicable to situations where the heat penetration depth is small compared to the lateral dimensions of the object. If the fabric burns and you have BURN_AWAY=T, then the fabric should not exist on the next layer of cells, and it will in your setup.
--
You received this message because you are subscribed to the Google Groups "FDS and Smokeview Discussions" group.
To unsubscribe from this group and stop receiving emails from it, send an email to fds-smv+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/fds-smv/d1af6d4d-707f-45b6-8d09-7c9dc3c40208%40googlegroups.com.
MP
Jan 7, 2020, 10:36:43 AM1/7/20
to FDS and Smokeview Discussions
Hello Randy, thanks for the reply.
Is BULK_DENSITY must to define in burn away because I have seen many examples in which it is not defined. I know OBST disappears based on bulk density and cell volume.
On Sunday, January 5, 2020 at 12:03:59 AM UTC+1, Randy McDermott wrote:
If by "real" you mean "correct", that is difficult to assess, which is likely why no one has responded. I do not see the point of putting a fabric layer on the back. I would hope your grid resolution is less than 2 m, you are not going to accurately mimic 3D pyrolysis behavior. The pyrolysis model is a 1D model, so it is applicable to situations where the heat penetration depth is small compared to the lateral dimensions of the object. If the fabric burns and you have BURN_AWAY=T, then the fabric should not exist on the next layer of cells, and it will in your setup.
To unsubscribe from this group and stop receiving emails from it, send an email to fds...@googlegroups.com.
Randy McDermott
Jan 7, 2020, 12:05:53 PM1/7/20
to FDS and Smokeview Discussions
If BULK_DENSITY is not present then a SURFACE_DENSITY is computed from the material layers.
To unsubscribe from this group and stop receiving emails from it, send an email to fds-smv+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/fds-smv/bf1e4ef9-36bc-42b8-996c-841d839ab3cf%40googlegroups.com.
Reply all
Reply to author
Forward
0 new messages