Replace INERT with COLDWALL?

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Still seems to be confusion from users about what INERT means.  I think in
part that the name is easily misconstrued.  In keeping with the concept of
Science 2.0, I am opening an issue to discuss this.

Would we be be better off replacing INERT with COLDWALL (we can add a line
to change INERT to COLDWALL to maintain backwards compatibility and write a
warning message)?

Original issue reported on code.google.com by drjfloyd on 3 Dec 2008 at 8:05

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For the record, tell me exactly what INERT/COLDWALL does.

Original comment by gfor...@gmail.com on 3 Dec 2008 at 8:26

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It is a solid surface that maintains the ambient temperature.

Original comment by mcgra...@gmail.com on 3 Dec 2008 at 8:38

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so,  heat transfer to or from this surface still occurs based upon its 
temperature
being at ambient?  Hence jason's suggestion to change the name to COLDWALL.

Original comment by gfor...@gmail.com on 3 Dec 2008 at 8:49

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Yes.   Or maybe not COLDWALL but AMBIENT_WALL or something that more actually
reflects what the surface really is.  

Original comment by drjfloyd on 3 Dec 2008 at 8:58

• Removed labels: Priority-Low

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Is not an INERT wall the same as an ISOTHERMAL wall, a wall with fixed 
temperature ?

Original comment by Finn.Dra...@gmail.com on 4 Dec 2008 at 2:09

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Yes, the wall is ISOTHERMAL, but I would rather not use that term because we 
use it 
already on the MISC line, meaning that there are no temperature changes allowed 
in 
the calculation.

Original comment by mcgra...@gmail.com on 4 Dec 2008 at 2:22

• Removed labels: Type-Defect

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in the original FDS the default condition was adiabatic.in fact it said is an 
adiabatic, inert wall. i'm sure the default has been changed for some time now. 
But 
i need some clarification on this now as well. 
my understanding from the discussions and User manual is that the Inert 
boundary 
condition absorbs heat based on the temperature gradient between the gas 
temperature 
and 20deg but doesn't heat up . how much heat does the inert surface absorb or 
what 
it is similar to e.g. concrete, block since you've suggested replacing with 
coldwall? 

Original comment by adrienne...@gmail.com on 19 Jan 2009 at 6:10

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The original version assumed that there was no convective heat transfer to an 
INERT 
wall -- that is, the wall was the same temperature as the gas. This assumption 
was 
based on the fact that most building materials have low thermal conductivities 
and 
are good insulators.

We kept the name INERT, even though now it refers to an ambient temperature 
solid. 
The heat transfer to it is

q" = eps*sigma*(T_eff^4-T_amb^4) + h*(T_g-T_amb)

where T_eff is the "effective" gas temperature from the standpoint of radiation 
transport and T_g is the near wall gas temperature. T_eff is not calculated 
explicitly, but rather a detailed radiation heat transfer calculation is used 
to 
predict the radiative heat flux to the wall. 

Think of an INERT solid as something that never heats up, like a piece of steel 
that 
has cold water constantly flowing across its back side. We recommend that this 
BC 
not be used -- it is better to assign actual material properties to everything. 
But 
we have to have a default nonetheless. 

Original comment by mcgra...@gmail.com on 21 Jan 2009 at 1:43

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before releasing 5.4.0, do we wish to take action on changing INERT to 
something more
meaningful?

Original comment by drjfloyd on 9 Jun 2009 at 8:32

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If you do, INERT should still work. Maybe just alias it somehow. I think most 
people 
have become aware of INERT means. Changing it might confuse things more.

Original comment by mcgra...@gmail.com on 9 Jun 2009 at 9:17

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No real groundswell of support for or against the idea, so I won't take any 
action.

Original comment by drjfloyd on 27 Jul 2009 at 12:50

• Changed state: WontFix