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

Boundary Conditions problem

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 27, 2013, 07:00
Default Boundary Conditions problem
  #1
Member
 
Osman
Join Date: Oct 2012
Location: Japan
Posts: 53
Rep Power: 13
o_mars_2010 is on a distinguished road
I have developed a code to solve 2D Navier stokes equation in a channel.
I have used Immersed boundary method to simulate the vibration of a cantilever beam in the channel.
The problem is that i do not know the direction of flow.
So i can not specifiy which boundary to be inlet and which boundary to be outlet.
Thus, i have to set both of the boundary to be Open Boundary.
My question is:
Waht should be the pressure and velocity boundary conditions on both boundaries ???
Please Help me.
o_mars_2010 is offline   Reply With Quote

Old   July 8, 2013, 03:04
Default
  #2
New Member
 
Join Date: Jun 2013
Posts: 1
Rep Power: 0
mxinfernal is on a distinguished road
I assume that any flow created is going to be due to the vibration of the beam -- hence the open channel.

In that case,

jj = 1:ny
u(1,jj) = u(2,jj)
u(nx,jj) = u(nx-1,jj)

You get the idea.
mxinfernal is offline   Reply With Quote

Old   July 8, 2013, 03:10
Default
  #3
Member
 
Osman
Join Date: Oct 2012
Location: Japan
Posts: 53
Rep Power: 13
o_mars_2010 is on a distinguished road
i applied neumann boundary conditions for velocity
Dirichlet boundary conditions for pressure
P_inlet=0
p_outlet=0
The code works very well.

However, when i change the P_outlet to have a value for example 2 Pascal
the code fails and blow up.

Do you have any suggestions ??
o_mars_2010 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
Implementation of boundary conditions for FVM Tom Main CFD Forum 7 August 26, 2014 06:58
An error has occurred in cfx5solve: volo87 CFX 5 June 14, 2013 18:44
Problem with Boundary conditions Mahiboobswamulu Main CFD Forum 10 August 26, 2003 14:24
boundary conditions problem reinaldo kuhn Phoenics 1 March 27, 2003 12:46
Boundary conditions? Tom Main CFD Forum 0 November 5, 2002 02:54


All times are GMT -4. The time now is 16:44.