[Nek5000-users] heat flux BC

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

Hi again Neks,

Sorry to ask again on these problem as there is no answer yet. I've been
trying to understand how the flux boundary condition works in here because
I've tried to work on both nondimensional and dimensionalized problem.
However, if I put constant value for the heat flux at the boundary in
userbc, I keep getting a constant temperature value after a developed
length in the downstream which should not be the case as the flow
temperature should keep increasing by the energy in especially for the
dimensionalized problem. Would anyone mind to share with me your knowledge
on this? Thanks

Muhsin


---------- Forwarded message ----------
From: Muhsin Mohd Amin <mmohdamin1 at sheffield.ac.uk>
Date: 1 April 2015 at 18:21
Subject: heat flux BC
To: nek5000-users at lists.mcs.anl.gov


Hi Neks,

I still trying to understand the calculation works in Nek5000
Sorry for some basic questions as not much of example on the flux BC:

1. If I put the boundary condition as flux, do I need to calculate the
resultant heat transfer coefficient or can I just obtain thoroughly from
the code? because I haven't found the HTC output any inside the code, but
whenever I grab the 'HC' it gives me some value. So what would be the value
of HC that I obtain there if I cannot get it directly from the code?

2. If I specify the flux number in the userbc for nondimensionalized
equation, how the deltaT is normalized is it to the bulk temperature?

3. All values that specified in the usr file for dimensionalized has to be
SI unit isn't it? as the flux should be in W/m2?


Regards,
-- 
Muhsin Mohd Amin
Graduate Student
Department of Mechanical Engineering
The University of Sheffield



-- 
Muhsin Mohd Amin
Graduate Student
Department of Mechanical Engineering
The University of Sheffield
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