[Nek5000-users] nelgv in uservp of conj_ht

[nek5000-users at lists.mcs.anl.gov]

Correct -- Case 1 is the right way..  (Sorry, my previous answer was off the mark as I misinterpreted the question..)

The point is that properties do not have to be continuous.  So in one element (solid), you have a property
all the way up to and including the interface.  In another (fluid), you have a different property all the way
up to an including the interface.   In this way, the integrand in the variational formulation sees piecewise
smooth functions and you get an excellent (sometimes exact) approximation to the integral of the step function.

Paul

________________________________________
From: nek5000-users-bounces at lists.mcs.anl.gov [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
Sent: Tuesday, January 24, 2017 11:41 AM
To: nek5000-users at lists.mcs.anl.gov
Subject: Re: [Nek5000-users] nelgv in uservp of conj_ht

Case (1) is correct way to impose properties for the solid. The interface condition will match the fluxes (in a weak sense) while heat capacity can discontinuous.

-----Original message-----
> From:nek5000-users at lists.mcs.anl.gov <nek5000-users at lists.mcs.anl.gov>
> Sent: Tuesday 24th January 2017 17:28
> To: nek5000-users at lists.mcs.anl.gov
> Subject: [Nek5000-users] nelgv in uservp of conj_ht
>
> Hello All,
> I have a question in uservp of conjugate heat transfer. I am trying to modify the conjugate heat transfer problem (with additional passive scalars) and use for solving MHD problem with vector potential approach.
>
> I tested the conjugate heat transfer case changing the IF condition in uservp in following ways.
>
> Case 1:
>         if (ieg .gt. nelgv) then  ! properties in the solid
>             udiff   = 0.1*param(8) ! conductivity
>             utrans  = 1.0
>          endif
>
> Case 2:
>       if (y .ge. 1.5D0) then
>               udiff= 0.1*param(8)
>       elseif (y. le. 0.5D0) then
>               udiff= 0.1*param(8)
>       else
>               udiff   = param(8)
>       endif
>
> I got a small difference in the temperature profile at the interface between solid and fluid.
> Could you please let me know, how do the above two cases affect the conditions imposed at the interface (what is the mathematical treatment and how does it change).
> Thank you in advance.
>
> Yours sincerely,
> Sandeep
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