# problem with surface integrals

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

 July 13, 2001, 08:48 problem with surface integrals #1 tibor Guest   Posts: n/a on the surface (with an outflow boundary condition) area-weighted average velocity magnitude is smaller then area-weighted average Z-velocity.. how it's possible?

 July 13, 2001, 12:39 Re: problem with surface integrals #2 Scott Whitney Guest   Posts: n/a I've seen the exact same problem that you are describing. For me thus usually has a less than 1% error. These surface integrals are only approximate, thus one can't be compared to the other. If you have significantly more than 1% error, then there might be an actual Fluent problem and they should be contacted.

 July 13, 2001, 17:06 Re: problem with surface integrals #3 Tamer Elsoukkary Guest   Posts: n/a I tested just counter flow in an annulaus where two different fluids are separated by wall and to my surprise when I specified the inlet as velocity inlet for both fluids the surface integral flow rate was changing between iterations! where it should be constant because velocity is specified!! How can that be possible!!!!

 July 16, 2001, 05:07 Re: problem with surface integrals #4 bas Guest   Posts: n/a I've seen the same phenomena and I think it's something like this. Velocity magnitude is a vectorial sum of x-, y- and z- velocity. When you have velocity component besides your primary flow (in z-direction), the velocity magnitude will be larger then the components itself.

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post everest ANSYS Meshing & Geometry 44 April 14, 2016 06:41 skyblue_mech Main CFD Forum 0 June 8, 2010 04:49 jeevan kumar CFX 0 August 13, 2008 01:54 Ale FLUENT 2 October 16, 2002 15:35 Chie Min CFX 5 July 12, 2001 23:19

All times are GMT -4. The time now is 11:18.