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

Considering the flow through a dense net / grid

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 31, 2012, 15:04
Default Considering the flow through a dense net / grid
  #1
Senior Member
 
---------
Join Date: Oct 2010
Posts: 302
Rep Power: 8
saisanthoshm88 is on a distinguished road
I have a grid like structure in the flow path and I'd like to consider it's effect with out actually meshing it.

The attached image shows the sructure / surface im talking about.

I'd like just keep it as a plane surface with out actually meshing those small holes but considering their effect by some means.

Could some one please tell me how to do this.
Attached Images
File Type: jpg flowgrid.JPG (49.4 KB, 6 views)
__________________
Best regards,
Santhosh.
saisanthoshm88 is offline   Reply With Quote

Old   July 31, 2012, 15:22
Default
  #2
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 486
Rep Power: 9
evcelica is on a distinguished road
use a porous domain to represent the pressure drop WRT flow. you can calculate the pressure drop curve with orifice calculations or actually model a single representative area of it.

The solver theory manual has a lot of documentation on this, I'd suggect you check out all the options and how the pressure drop is calculated.
evcelica is offline   Reply With Quote

Old   July 31, 2012, 15:32
Default
  #3
Senior Member
 
---------
Join Date: Oct 2010
Posts: 302
Rep Power: 8
saisanthoshm88 is on a distinguished road
Could you please let me know if there is some thing like a area porosity as it is just a surface with such holes over it.
__________________
Best regards,
Santhosh.
saisanthoshm88 is offline   Reply With Quote

Old   July 31, 2012, 15:46
Default
  #4
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 486
Rep Power: 9
evcelica is on a distinguished road
volume porosity is just one of the options, but all this does is increase your velocity through the domain if you choose the true velocity option. You also have to define the curve of how the pressure decreases with velocity. for this you define the permeability or loss coefficient or both, as per the equation below:

DP per unit length = -(Viscosity/k.perm)*Velocity - (density/2)*Loss.Coefficient*Velocity^2

Where the velocity is either the true velocity or superficial as set in the porous options tab.

There are many ways to do this though, I'd check the theory manual.

Last edited by evcelica; August 1, 2012 at 20:14. Reason: Fixed equation
evcelica 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
Grid independent problem for lid-driven flow dpc-buaa Main CFD Forum 0 February 22, 2011 23:24
Grid generation cross flow over circular cylinder Yanma OpenFOAM Native Meshers: blockMesh 0 July 7, 2010 08:02
Grid for swirling flow Stephen Main CFD Forum 6 October 24, 2008 17:57
On grid independent solution for pulsatile flow David FLUENT 4 June 8, 2005 16:20
computation about flow around a yawed cone Tylor Xie Main CFD Forum 0 June 9, 1999 07:33


All times are GMT -4. The time now is 14:59.