CFD Online Logo CFD Online URL
Home > Forums > OpenFOAM Running, Solving & CFD

which boundary condition is true?

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

LinkBack Thread Tools Display Modes
Old   January 8, 2013, 06:24
Default which boundary condition is true?
Senior Member
immortality's Avatar
Join Date: Oct 2012
Location: Iran
Posts: 2,205
Rep Power: 18
immortality is on a distinguished road
I have used 3 types of boundary conditions with three different results!
The patch i assigned BC on is outflow.these scenarios are examined:
1)firstly pressure is specified through p0 as isentropic formul:


U and T are zero this pressures are obtained less than expected.
2)at second i set

And U and p are assumed zero gradient.
This approach results in more higher pressures.
3)both p and T are specified:

T=T0-(gama-1)/(2*gama*R)*U^2 (as second case)

This approach leads to diverge after 200 iterations.

So as it tooks one month so far and remaind a little time for me why these conditions result so differently?whats the cause or the causes?
Any knowledge,advice and idea is much appreciated.
Thanks for attention.
immortality 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
Radiation interface hinca CFX 15 January 26, 2014 18:11
Setting outlet Pressure boundary condition using CAFFA code Mukund Pondkule Main CFD Forum 0 March 16, 2011 04:23
Domain Imbalance HMR CFX 3 March 6, 2011 21:10
asking for Boundary condition in FLUENT Destry FLUENT 0 July 27, 2010 00:55
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 05:05

All times are GMT -4. The time now is 02:43.