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Old   May 25, 2015, 08:11
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Hello
I have to model a heat transfer on the steel screws. How to simplify and model this problem. The black cube is filled with screws. Green cube is a fluid domain. On the top and the bottom wall I have temperature 700 C.
Initialization
Fluid domain 20 C
screws 20 C.
Transient analysis - 9 hours.
How to model black domain ??
Porosity, multiphase, particle tracking ??
Best regards from poland
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Old   May 25, 2015, 10:05
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Model the thousands of screws as a porous medium.
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Old   May 26, 2015, 03:09
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Thanks
And how to determine interfacial loss coefficient ??
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Old   May 26, 2015, 03:11
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sorry
interfacial area density ??
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Old   May 26, 2015, 08:25
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Why do you need the interfacial area density? This is a single phase simulation isn't it?

Regarding loss coefficients: they can be found in text books to start with.
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Old   May 29, 2015, 02:12
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thanks for Your answer
I define porous domain. Everything is good when I define heat transfer between
fluid domain and porous.
But when i define velocity from left wall to right wall (fluid domain) imbalances go high and after couple time steps i get error overflow.
What I do wrong??
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Old   May 29, 2015, 11:09
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Did you try increasing your Source Coefficient?
Is it large to begin with?
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Old   May 30, 2015, 03:26
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Hello
What do You mean ??
I have another questions
below interface area density is heat transfer coefficient
can i take value form previous simuation with one screw which I determine to 2
W/m2K?? And what about heat transfer on solid? Can Ileave adiabatic ??
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Old   May 30, 2015, 03:30
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so when air with defined velocity going into porous domain all imbalances goes high and after couple timesteps I get error overflow
Anyone knew any tutorials with immersed porous medium like in my case ??
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Old   June 1, 2015, 03:08
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Can anyone help me ??
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Old   June 2, 2015, 09:32
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Look up Source Coefficient in CFX help. I briefly looked over your post and it seems like this could help you.
Take a look, and ask more questions after. If you need more help, describe your problem more, and perhaps post some pics of your setup and settings.
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Old   July 22, 2015, 06:48
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thanks a lot of your answers
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Old   July 23, 2015, 09:37
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can anyone tutorials for porous medium with heat transfer but immersed (all walls) on the fluid domain ??
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