ut with a
>>>> thermal diffusivity is simply not the correct representation of your
>>>> physical situation. The actual conservation equation for thermal energy is
>>>> (neglecting convection and source terms)
>>>> > >
>>>> > >
; from the correct conserved quantities. I would guess that if you run it
>>> with any rho, c_p that are the same in the concrete and insulator, you will
>>> get the correct result with the "alpha form" because, being both constant
>>> and uniform, they can be swept int
than unity. I have realised that the
>> equation should be specified as
>> > >
>> > >
>> > > eqn = TransientTerm(coeff=C) == DiffusionTerm(coeff=k)
>> > >
>> > >
>> > > where the volumetric heat capacity is C = rh
ho*c_p) has a value other than unity. I have realised that the
> equation should be specified as
> > >
> > >
> > > eqn = TransientTerm(coeff=C) == DiffusionTerm(coeff=k)
> > >
> > >
> > > where the volumetric heat capacity is C = rho * c_p
thermal
> > conductivity. For a steady case, this equation reduces to
> > 'DiffusionTerm(coeff=k)==0' and gives a correct result.
> >
> >
> > I have attached a figure with the updated comparison of FiPy and TEMP/W for
> > an insulated concrete slab, show
iffusionTerm respectively.
>
>
> Many thanks,
>
> Conor
>
>
> From: fipy-boun...@nist.gov<mailto:fipy-boun...@nist.gov>
> [fipy-boun...@nist.gov<mailto:fipy-boun...@nist.gov>] on behalf of Conor
> Fleming [conor.flem...@eng.ox.ac.uk<mailto:conor.flem
to
> add a note to the documentation page 'examples.diffusion.mesh1D',
> explaining that for some applications, e.g. the heat equation, it is
> appropriate to separate the (thermal) diffusivity into two portions, which
> act on the TransientTerm and DiffusionTerm respectively.
>
, explaining that
> for some applications, e.g. the heat equation, it is appropriate to separate
> the (thermal) diffusivity into two portions, which act on the TransientTerm
> and DiffusionTerm respectively.
>
>
> Many thanks,
>
> Conor
>
>
> From: fipy-bou
nd DiffusionTerm respectively.
>
>
>
> Many thanks,
>
> Conor
>
>
> ------------------
> *From:* fipy-boun...@nist.gov [fipy-boun...@nist.gov] on behalf of Conor
> Fleming [conor.flem...@eng.ox.ac.uk]
> *Sent:* 08 August 2014 17:24
> *To:* fipy@nist.gov
&
uk]
Sent: 08 August 2014 17:24
To: fipy@nist.gov
Subject: RE: Unexpected result, possibly wrong, result solving 1D unsteady heat
equation with spatially-varying diffusion coefficient
Hi Kris,
Thank you for the prompt response. You are right - altering the insulation
conductivity in the FiPy m
@nist.gov
Subject: Re: Unexpected result, possibly wrong, result solving 1D unsteady heat
equation with spatially-varying diffusion coefficient
Conor,
if you reduce the thermal conductivity in the insulation to about 0.1, the fipy
solution looks about like the other model (the knee in T is about at
Conor,
if you reduce the thermal conductivity in the insulation to about 0.1, the
fipy solution looks about like the other model (the knee in T is about at
400 degrees C). Is there an issue with how your compute or specify this in
fipy or the other model?
Kris
On Fri, Aug 8, 2014 at 9:35 AM, C
Hi,
I am using FiPy to determine the depth of heat penetration into concrete
structures due to fire over a certain period of time. I am solving the unsteady
heat equation on a 1D grid, and modelling various scenarios, e.g.
time-dependent temperature boundary condition, temperature-dependent dif
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