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

Problem on boundary conditions

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 19, 2003, 03:28
Default Problem on boundary conditions
  #1
Miko
Guest
 
Posts: n/a
Hi all! I have trouble when I define inlet/outlet. I'm confused by how to set pressure. If I want to set the static pressure of Point A (inlet) 50 Pa greater than that of Point B (outlet) and the initial velocity of inlet is zero, how can I put it into practise? Is it right that I specify Mass and Momentum of inlet as Static Pressure with 50 Pa and outlet 0 Pa?

Best regards!

Miko
  Reply With Quote

Old   June 20, 2003, 01:11
Default Re: Problem on boundary conditions
  #2
Neale
Guest
 
Posts: n/a
While this physically makes sense it does not constrain momentum and you may have a lot of difficulty getting a solution as a result. i.e. any momentum flow will give you the solution you want.

I suggest that you run total pressure inlet and mass flow outlet or static pressure outlet until you get the inlet velocity you want.

Neale
  Reply With Quote

Old   June 20, 2003, 08:22
Default Re: Problem on boundary conditions
  #3
Miko
Guest
 
Posts: n/a
Hi Neale!

Thank you for your guideline! But I still have problem to understand what you have said.

1. Why does my setting make sense but be unable to get a satisfied solution? Since I have a little idea on CFX modeling, I hope you can give me some explanation in point.

2. According to your suggest, what's the specfic value I should specify, such as total pressure inlet, mass flow outlet or static pressure outlet?

Thank you for your time!

Miko
  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
CG, BICGSTAB(2) : problem with matrix operation and boundary conditions moomba Main CFD Forum 2 February 17, 2010 04:37
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
Fluent accuracy and boundary conditions Paolo Lampitella FLUENT 0 June 12, 2008 06:25
Problem with Boundary conditions Mahiboobswamulu Main CFD Forum 10 August 26, 2003 13:24
boundary conditions problem reinaldo kuhn Phoenics 1 March 27, 2003 12:46


All times are GMT -4. The time now is 20:59.