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

laminar flow on flat plate

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 1, 2006, 12:44
Default laminar flow on flat plate
  #1
AmirFluid
Guest
 
Posts: n/a
I have used Patankar code to simulate laminar flow over flat plate. Results show some velocity overshoot just next to the plate surface. Also pressure has sudden rise at the first point above starting of the plate. does anyone know the reason?
  Reply With Quote

Old   September 2, 2006, 09:53
Default Re: laminar flow on flat plate
  #2
Siddharth
Guest
 
Posts: n/a
Dear Amir,

I don't have much idea about Patankar code. But most likely it is due to improper grid refinement near wall or near-wall treatment scheme that is used. Because velocity and hence pressure gradient is high in this region. For that you need either more number of cells near to wall or pick up good descretization scheme.

Regards,

Sidd
  Reply With Quote

Old   September 4, 2006, 05:05
Default Re: laminar flow on flat plate
  #3
mar
Guest
 
Posts: n/a
Hi Using 10 to 20 points in the boudnary layer you must find the Blasius solution for the laminar plate.

If your grid complies with these requirement the problem can be in the boundary conditions. First check the wall BC (u=v=0 dp/dn=0 dT/dn=0) Second the Inlet condition. Regarding the inlet you can have two choice: 1) you impose the Euler inlet condition because you simulate the leading edge (i.e. your plate doesn't start at i=1 but, for example at i=10 and from i=1 and i=9 you impose simmetry condition) 2) you impose a velocity profile at the inlet because you do not simulate the trailing edge (your plate starts at i=1 and so the Euler inlet condition is not valid).

  Reply With Quote

Old   September 7, 2006, 11:01
Default Re: laminar flow on flat plate
  #4
Bounecer
Guest
 
Posts: n/a
Please how to implement that same boundary conditions for airfoil and using structured O-grid
  Reply With Quote

Old   February 26, 2010, 06:24
Default
  #5
Member
 
varun
Join Date: Apr 2009
Posts: 35
Rep Power: 16
varunjain89 is on a distinguished road
hey....
i'm having the same problem... i'm taking u_freestream as 100.... velocity is shooting @ the point next to wall... and then gradually it is receding... some1 suggested me to have varible width b/w grid points along y-axis.... how do i exactly do that...???
varunjain89 is offline   Reply With Quote

Old   March 4, 2010, 08:01
Default
  #6
Member
 
varun
Join Date: Apr 2009
Posts: 35
Rep Power: 16
varunjain89 is on a distinguished road
i got the results........ who so ever encounters such problem.... the problem is with dx values you r taking..... they r too large... reduce them and your code works fine.....
varunjain89 is offline   Reply With Quote

Old   April 25, 2010, 12:07
Default
  #7
Member
 
Join Date: Jul 2009
Posts: 70
Rep Power: 16
nvtrieu is on a distinguished road
Hello everyone,

I've got the same problem with AmirFluid. In my simulation I used the flat plate that starts at x=0, so as Mar mensioned, the Euler inlet condition is not valid. Can anyone tell me what is the Euler condition here? I'll try to refine the mesh at x-direction as varunjain89 said.
Thanks for any help!
nvtrieu is offline   Reply With Quote

Old   June 22, 2010, 06:49
Default
  #8
Member
 
Ardalan
Join Date: Feb 2010
Location: Baku
Posts: 50
Rep Power: 16
Ardalan is on a distinguished road
can anyone send me the patankar code?????
I will be thankful
thelastarmageddon@yahoo.com

Last edited by Ardalan; June 22, 2010 at 08:01.
Ardalan 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
Boundary Layer of Laminar Flow over a Flat Plate Blasius_Pohlhausen_Crocco Main CFD Forum 12 September 30, 2013 18:35
Low Reynolds Number Flow over a Flat Plate Go FLUENT 4 August 28, 2013 06:19
incompressible, 2-D laminar flow over flat plate... varunjain89 Main CFD Forum 3 March 6, 2012 12:13
boundary layer trips in laminar flat plate flow David FLUENT 0 June 23, 2005 12:01
2d supersonic flow over flat plate puzzled Main CFD Forum 2 March 17, 2004 19:07


All times are GMT -4. The time now is 09:12.