heat transfer screws
 

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

Model the thousands of screws as a porous medium.

Thanks
And how to determine interfacial loss coefficient ??

sorry
interfacial area density ??

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.

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??
Best regards

Did you try increasing your Source Coefficient?
Is it large to begin with?

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 ??
Best regards

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 ??

Can anyone help me ??

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.

thanks a lot of your answers

can anyone tutorials for porous medium with heat transfer but immersed (all walls) on the fluid domain ??