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

Problem with SIMPLE algorithm

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

Like Tree1Likes
  • 1 Post By katakgoreng

Reply
 
LinkBack Thread Tools Display Modes
Old   December 27, 2009, 09:24
Default Problem with SIMPLE algorithm
  #1
Member
 
Join Date: Dec 2009
Posts: 42
Rep Power: 7
katakgoreng is on a distinguished road
I have written finite difference SIMPLE algorithm to solve the Navier Stokes equation in Matlab. My problem is that I don't know how to specify boundary condition for Poisseuille flow. If i specify inlet velocity, the solution tend to blowup. I suspect that somehow I don't specify the pressure boundary correctly.(In the matlab code if I specify the pressure boundary for inlet and outlet but no velocity boundary at the inlet, the solution does not blow up but the problem is that I cannot control the inlet velocity) I managed to solve Couette flow and Driven cavity problem with no problem though..Care to advice me on what I have to do. I attached also the code for the SIMPLE algorithm that I write..
Attached Images
File Type: jpg Fluid Domain.jpg (70.4 KB, 50 views)
Attached Files
File Type: zip FD_Method_Flow_Poisseuille.zip (2.8 KB, 56 views)

Last edited by katakgoreng; December 27, 2009 at 09:48. Reason: need to give mo info
katakgoreng is offline   Reply With Quote

Old   December 27, 2009, 11:13
Default boundary condition
  #2
Member
 
jk
Join Date: Jun 2009
Posts: 64
Rep Power: 8
jyothishkumar is on a distinguished road
You are solving flow in a duct basically. Use velocity inlet and pressure outlet bc. Which grid r u using ? colocated or staggered
jyothishkumar is offline   Reply With Quote

Old   December 27, 2009, 11:21
Default
  #3
Member
 
Join Date: Dec 2009
Posts: 42
Rep Power: 7
katakgoreng is on a distinguished road
Quote:
Originally Posted by jyothishkumar View Post
You are solving flow in a duct basically. Use velocity inlet and pressure outlet bc. Which grid r u using ? colocated or staggered
I'm using staggered grid..if i set the inlet velocity to v=1 and pressure outlet p=0, how about inlet pressure, do i need to extrapolate it with inner pressure?
katakgoreng is offline   Reply With Quote

Old   December 28, 2009, 00:02
Default
  #4
Member
 
jk
Join Date: Jun 2009
Posts: 64
Rep Power: 8
jyothishkumar is on a distinguished road
yes exactly. p(1).value = p(2).value where p is the pressure and numbers indicate the node location
jyothishkumar is offline   Reply With Quote

Old   December 28, 2009, 05:09
Default
  #5
Member
 
Join Date: Dec 2009
Posts: 42
Rep Power: 7
katakgoreng is on a distinguished road
Quote:
Originally Posted by jyothishkumar View Post
yes exactly. p(1).value = p(2).value where p is the pressure and numbers indicate the node location
hmmm..it's that simple? i'll try it..
for anyone who has run my code, do comment on what I have done..thanks in advance..
guanjingduibuqi likes this.
katakgoreng 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
SIMPLE algorithm in 3D cylindrical coordinates zouchu Main CFD Forum 1 January 20, 2014 18:02
A simple heat transfer problem ? iggor FLUENT 1 June 15, 2009 04:42
SIMPLE algorithm for collocated storage alex Main CFD Forum 4 April 8, 2008 23:48
DPM - simple problem (I think) Maciej FLUENT 0 November 9, 2005 17:28
? Simple CFD problem Davy Main CFD Forum 0 August 21, 1998 06:19


All times are GMT -4. The time now is 02:23.