Porous zone

raggiotti · January 3, 2017, 12:34

Hi guys!

I need a help! Pleas see the attachemnt.

I am trying to simulate a tube bank using porous zone. My velocity inlet is profiles, from another case.
I need to slow down the velocity instead of increasing.

The results I simulate with fluid porosity = 1

Anyone can help me?

KevinZ09 · January 4, 2017, 05:01

I'd need some more information to be able to help you better.

How are pictures 1 & 3 related, like picture 1 is a view of what plane? XZ? Do you want a porous zone in the highlighted zone of picture 3? And where is that highlighted zone in picture 1? And where's the inlet?

As for the porous medium zone, what are directions 1, 2 and 3? Is direction 2 the y-direction, as that seems to be the obstructed direction?

Now, as to what you're trying to do, are you saying you want to create a porous medium zone to slow down your flow? Because you won't be able to achieve that if you have a velocity profile as inlet (i.e., a fixed mass flow rate); you're gonna get an accelerating flow. Well, not in your case because you've got porosity = 1. Are you solving for the physical or superficial velocity? If you set a fixed mass flow rate as inlet, once the fluid enters the porous medium zone, it will accelerate if your porosity < 1. You'll see that back in your results if you solve for the physical velocity. If you solve for the superficial velocity, there won't be a change in velocity (v_sup = por*v_phys).

raggiotti · January 4, 2017, 07:27

How are pictures 1 & 3 related, like picture 1 is a view of what plane? XZ?

Picture 1 is from autocad, but we can consider YZ plane.

Picture 2 is XY plane.

Do you want a porous zone in the highlighted zone of picture 3?
Yes

And where is that highlighted zone in picture 1?
Where shows the drop pressure. The tube bank between the green and magenta.

And where's the inlet?
Where shows "Velocity inlet (profiles) 19 m/s

As for the porous medium zone, what are directions 1, 2 and 3?
1 - x
2 - y
3 - z

Is direction 2 the y-direction, as that seems to be the obstructed direction?
Yes

Are you solving for the physical or superficial velocity?
First I solved as superficial, after physical.

Kevinz09, I found the problem! I was using profile as velocity inlet from another case.
The outlet form this another case was the end a porous zone, so fluent wasn't able to recognize the velocity slow down for inlet of atual case.

I solved the previous case again, with a small geometry non-porous zone at the end, and used this outlet as profiles and my problem solved!

But thanks for the attention!

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January 4, 2017, 05:01		#2
KevinZ09 Senior Member Kevin Join Date: Dec 2016 Posts: 138 Rep Power: 9	I'd need some more information to be able to help you better. How are pictures 1 & 3 related, like picture 1 is a view of what plane? XZ? Do you want a porous zone in the highlighted zone of picture 3? And where is that highlighted zone in picture 1? And where's the inlet? As for the porous medium zone, what are directions 1, 2 and 3? Is direction 2 the y-direction, as that seems to be the obstructed direction? Now, as to what you're trying to do, are you saying you want to create a porous medium zone to slow down your flow? Because you won't be able to achieve that if you have a velocity profile as inlet (i.e., a fixed mass flow rate); you're gonna get an accelerating flow. Well, not in your case because you've got porosity = 1. Are you solving for the physical or superficial velocity? If you set a fixed mass flow rate as inlet, once the fluid enters the porous medium zone, it will accelerate if your porosity < 1. You'll see that back in your results if you solve for the physical velocity. If you solve for the superficial velocity, there won't be a change in velocity (v_sup = por*v_phys).

January 4, 2017, 07:27		#3
raggiotti New Member Rodrigo Raggiotti Join Date: Jul 2016 Posts: 3 Rep Power: 9	How are pictures 1 & 3 related, like picture 1 is a view of what plane? XZ? Picture 1 is from autocad, but we can consider YZ plane. Picture 2 is XY plane. Do you want a porous zone in the highlighted zone of picture 3? Yes And where is that highlighted zone in picture 1? Where shows the drop pressure. The tube bank between the green and magenta. And where's the inlet? Where shows "Velocity inlet (profiles) 19 m/s As for the porous medium zone, what are directions 1, 2 and 3? 1 - x 2 - y 3 - z Is direction 2 the y-direction, as that seems to be the obstructed direction? Yes Are you solving for the physical or superficial velocity? First I solved as superficial, after physical. Kevinz09, I found the problem! I was using profile as velocity inlet from another case. The outlet form this another case was the end a porous zone, so fluent wasn't able to recognize the velocity slow down for inlet of atual case. I solved the previous case again, with a small geometry non-porous zone at the end, and used this outlet as profiles and my problem solved! But thanks for the attention!