CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Solid Properties Setup In Simulation of Porous Media

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   March 21, 2012, 21:54
Question Solid Properties Setup In Simulation of Porous Media
  #1
New Member
 
Samuel
Join Date: Nov 2011
Posts: 12
Rep Power: 6
Modest Cat is on a distinguished road
Hi guys~

In order to simulate heat transfer between gas and solid in porous media, I add an additional UDS which represents the solid energy equation. Meanwhile, I still want to use the porous media(PM) energy equation given by FLUENT to calculate the heat transport in gas. So I have to remove all solid items in PM equation by setting all solid properties (Cp\density\conductivity) ZERO!!!

Is this the right way to build the double energy equation model?

Regards
Modest Cat is offline   Reply With Quote

Old   March 24, 2012, 01:22
Default
  #2
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,227
Rep Power: 20
LuckyTran will become famous soon enough
Quote:
Originally Posted by Modest Cat View Post
Hi guys~

In order to simulate heat transfer between gas and solid in porous media, I add an additional UDS which represents the solid energy equation. Meanwhile, I still want to use the porous media(PM) energy equation given by FLUENT to calculate the heat transport in gas. So I have to remove all solid items in PM equation by setting all solid properties (Cp\density\conductivity) ZERO!!!

Is this the right way to build the double energy equation model?

Regards
The Porous Media energy equation already accounts for thermal transport due to both solid and gas. You do not need to do anything. The effective thermal conductivity of the porous section is calculated with a weighted average of the solid/fluid contributions (through porosity).

Don't forget that in addition to the material properties, you also need to specify the porosity! If you want to calculate heat transport only due to gas, an even easier method is to set the porosity to 0. porosity = 1 will give you the opposite extreme. But changing the porosity will also change the way the momentum is dealt with, so this is probably not what you want to do in this case.
LuckyTran is offline   Reply With Quote

Old   March 26, 2012, 03:20
Default
  #3
New Member
 
Samuel
Join Date: Nov 2011
Posts: 12
Rep Power: 6
Modest Cat is on a distinguished road
Quote:
Originally Posted by LuckyTran View Post
The Porous Media energy equation already accounts for thermal transport due to both solid and gas. You do not need to do anything. The effective thermal conductivity of the porous section is calculated with a weighted average of the solid/fluid contributions (through porosity).

Don't forget that in addition to the material properties, you also need to specify the porosity! If you want to calculate heat transport only due to gas, an even easier method is to set the porosity to 0. porosity = 1 will give you the opposite extreme. But changing the porosity will also change the way the momentum is dealt with, so this is probably not what you want to do in this case.
Dear LuckyTran,

Thanks for your reply. I think I completely understand your words. But one assumption that FLUENT make is thermal equilibrium between gas and solid, and this is not the situation of mine, which contains combustion and sufficient convection heat transfer in the model.

So, when I use the equation which FLUENT has to solve the gas energy equation (only), I can set the porosity 0. However, with this, I cannot using the physical velocity, as you said.

What I want to do is keep the porosity (like 0.39), and at the same time, remove the influence of solid, just like setting porosity 0.

I just don't know what I've done is reasonable or not (-by setting all solid properties 0).

I hope I've express my thought clearly.

Kind regards,
Samuel
Modest Cat is offline   Reply With Quote

Old   March 26, 2012, 03:37
Default
  #4
Senior Member
 
Lucky Tran
Join Date: Apr 2011
Location: Orlando, FL USA
Posts: 1,227
Rep Power: 20
LuckyTran will become famous soon enough
Quote:
Originally Posted by Modest Cat View Post
Dear LuckyTran,

Thanks for your reply. I think I completely understand your words. But one assumption that FLUENT make is thermal equilibrium between gas and solid, and this is not the situation of mine, which contains combustion and sufficient convection heat transfer in the model.

So, when I use the equation which FLUENT has to solve the gas energy equation (only), I can set the porosity 0. However, with this, I cannot using the physical velocity, as you said.

What I want to do is keep the porosity (like 0.39), and at the same time, remove the influence of solid, just like setting porosity 0.

I just don't know what I've done is reasonable or not (-by setting all solid properties 0).

I hope I've express my thought clearly.

Kind regards,
Samuel
I understand now what you are trying to do. It should be fine if your UDS/UDF is set up properly. The solid properties should not appear anywhere else to mess up anything. I also believe your approach is correct. Again, just make sure the UDS and any UDF's are doing their job!
LuckyTran is offline   Reply With Quote

Old   March 26, 2012, 05:00
Default
  #5
New Member
 
Samuel
Join Date: Nov 2011
Posts: 12
Rep Power: 6
Modest Cat is on a distinguished road
Quote:
Originally Posted by LuckyTran View Post
I understand now what you are trying to do. It should be fine if your UDS/UDF is set up properly. The solid properties should not appear anywhere else to mess up anything. I also believe your approach is correct. Again, just make sure the UDS and any UDF's are doing their job!
Thanks again~
Modest Cat is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
transient Simulation with porous media Chrisi1984 OpenFOAM Running, Solving & CFD 6 August 26, 2015 16:13
Porous Media coupled with internal flow Samuel Andrade FLUENT 2 August 26, 2012 09:43
porous media in CFX X. Shen CFX 2 September 4, 2010 06:46
Porous media : simulation of an heat exchanger Arnaud FLUENT 6 October 19, 2009 04:45
Tube bundle simulation using porous media Jitendra Main CFD Forum 2 April 13, 2004 07:57


All times are GMT -4. The time now is 07:22.