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

Pressure-Velocity coupling -> general question

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 14, 2010, 12:05
Default Pressure-Velocity coupling -> general question
  #1
New Member
 
Smith, John
Join Date: Nov 2010
Posts: 8
Rep Power: 6
quattro123 is on a distinguished road
Hello, since i dont know exactly how the pressure velocity couplings influence the solution, i tried a experiment.

My test case was a lid-driven cavity where only the lid is moving (the top of the quader) in x-direction.


Now i simulated the same case with the three different coupling algorithms:

SIMPLE, SIMPLEC and PISO.


Then i plotted the velocities of x and y direction on both x and y middle axis to compare them.



The thing is the iteration of the lid.
From a fluent tutorial I have the information to iterate from neither the fluid nor the lid, just put a small value for the x velocity and a very small value for the y velocity.


I did it, i followed the tutorial very carefully and all of my velocity plots look very different. I thought thats okay.




Now i did also another iteration, where i initalized from nothing. i didnt select any item or entered any initial velocity in the initialize window and i iterated.
I thought this makes no chance, except that it will need much more iterations. But then i plotted all the velocities again for the different couplings and i realized that all of them are NEARLY the same, they are very very close the same.





So, which one is the right way to do that?
I guess the velocity couplings have to be different, dont they?

Or will i see just a difference when i use a coarse mesh?

Maybe one can shortly introduce me the basics/difference of the 3 algorithms? i already read the fluent manual, but i understood nothing of this.




Kind regards!
quattro123 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
Velocity Pressure Coupling Chris Lucas OpenFOAM 1 November 2, 2010 17:14
Pressure Velocity coupling problem Sunho park OpenFOAM Running, Solving & CFD 0 August 4, 2010 00:22
Unsteady flow- pressure velocity coupling Hooman Main CFD Forum 0 June 7, 2010 10:31
Pressure - velocity coupling student CFX 0 March 26, 2008 12:36
Does star cd takes reference pressure? monica CD-adapco 1 April 19, 2007 11:26


All times are GMT -4. The time now is 06:51.