CFD Online Logo CFD Online URL
Home > Forums > FLUENT

Pressure boundary condition issue

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

LinkBack Thread Tools Display Modes
Old   April 6, 2012, 13:35
Default Pressure boundary condition issue
New Member
Join Date: Mar 2009
Posts: 20
Rep Power: 10
Vijay is on a distinguished road
1. I am modeling a manifold of an engine with an inlet and 4 outlets (cylinders)

2. I used UDF to define transient pressure boundary condition at four outlets.

3. My goal is to analyze airflow from intake to 4 cylinders at different time steps. Some cylinders are closed and some are open during different times.

4. For example, in first 20 steps air should flow only to cylinder 1 since remaining cylinders are closed. I modeled this by assigning same pressure at intake and other 3 cylinders.

5. My issue is I see a airflow from cylinder 2,3,4 to cylinder 1. It appears that this is happening due to the pressure drop between intake and cylinder 1 is same as pressure drop between cylinder 2 or 3 or 4 and cylinder 1.

Please let me know if this is due to boundary condition specification issue. I don't see any problem in UDF since I modeled the same with steady pressure boundary condition and I face the same issue.

Any help is appreciated.
Vijay is offline   Reply With Quote


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
mixed inflow/outflow downstream boundary condition question peob OpenFOAM Running, Solving & CFD 3 February 3, 2017 11:54
Water subcooled boiling Attesz CFX 7 January 5, 2013 04:32
Pressure Boundary condition abishek FLUENT 1 July 28, 2008 08:14
what the result is negatif pressure at inlet chong chee nan FLUENT 0 December 29, 2001 06:13

All times are GMT -4. The time now is 02:07.