CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

Honeycomb Porous medium

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 25, 2021, 15:36
Post Honeycomb Porous medium
  #1
New Member
 
Ahmed Ibrahim Abdalla
Join Date: Aug 2021
Posts: 3
Rep Power: 2
ahmed ibrahim is on a distinguished road
Hello everyone
I'm working on a project to reduce the heat transfer in plate in a square pipe. i have to create a porous medium in this plate. my question is, how to define the honeycomb parameters in CFX ?
ahmed ibrahim is offline   Reply With Quote

Old   August 27, 2021, 06:21
Smile
  #2
New Member
 
Ahmed Ibrahim Abdalla
Join Date: Aug 2021
Posts: 3
Rep Power: 2
ahmed ibrahim is on a distinguished road
can anyone help me please
ahmed ibrahim is offline   Reply With Quote

Old   August 27, 2021, 06:44
Default
  #3
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 16,871
Rep Power: 132
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
Have you looked in the documentation and read what parameters CFX needs to define a porous region? I would have thought that was the obvious place to start.

If you have read the documentation - then what are you having troubles defining?
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Old   September 9, 2021, 22:01
Question
  #4
New Member
 
Ahmed Ibrahim Abdalla
Join Date: Aug 2021
Posts: 3
Rep Power: 2
ahmed ibrahim is on a distinguished road
Hello Ghorrocks,
thank you for your Answer. I have red the documentation and what parameters CFX needs to define a porous region. I understood that a Honeycomb or Perforated plat are Anistropic Porous medium and they could have Directional Loss Coefficient. Ialso have red some letrature about Honeycomb/ Perforated plate and i saw in some of them the Kperm was 5.73 mm/s ( which i couldnt implement in CFX ) and some of them was 1E-5,-6, -9 , -10 ,,,,,m^2 which i could implement in CFX.
I still dont understand how CFX understand that these numbers are for honeycomb or other thing.
one honeycomb can have many deffirent values.
how can i define it exactly to get the result i want.
ahmed ibrahim is offline   Reply With Quote

Old   September 11, 2021, 07:40
Default
  #5
siw
Senior Member
 
Stuart
Join Date: Jul 2009
Location: Portsmouth, England
Posts: 670
Rep Power: 23
siw will become famous soon enough
Do you have the experimental data for the pressure drop (\Delta p) across the plate as a function of volumetric flow rate (Q) or superficial velocity (U_{s})? This is the velocity associated with the volumetric flow rate and frontal area (Q=AU_{s}), not the true velocity within the porous media and the area of the filter pathways.

For a subdomain you can input permeability in units of [m^2] and loss coefficient in units of [1/m], but the latter might not be significiant. Let us assume you have a plot of \Delta p vs Q and curve fitted to give \Delta p=aQ+bQ^{2} which is also \Delta p=aAU_{s}+b\left(AU_{s}\right)^{2}. CFX-Solver Theory Gude explains the Darcy-Forchheimer equation. You can then determine your K_{perm} and K_{loss} from the curve fit, fluid properites (\rho and \mu) and filter thickness (\Delta n):

aA=\frac{\mu \Delta n}{K_{perm}} \\rightarrow \ K_{perm}=\frac{\mu \Delta n}{aA}
bA^{2}=K_{loss} \frac{\rho}{2} \Delta n \\rightarrow \ K_{loss}=\frac{2bA^{2}}{\rho \Delta n}

Use the directional streamwise multipler to ensure this is applied to the streamwise direction only.
siw is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
UDF for Sorption in Species Transport through Porous Medium Kosch Fluent UDF and Scheme Programming 6 October 21, 2020 18:46
Velocity inlet boundary condition for porous medium Chander CFX 3 March 11, 2012 22:18
Lack of local thermal equilibrium in porous medium Chander CFX 4 March 4, 2012 05:07
How to use non-equilibrium thermal model for porous medium in Ansys CFX 13.0? Chander CFX 3 November 28, 2011 15:26
porous medium and reactions Valeria FLUENT 1 July 10, 2009 04:58


All times are GMT -4. The time now is 04:07.