CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Gravity, UDF Source & Operating Density. HELP ME!

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

LinkBack Thread Tools Search this Thread Display Modes
Old   November 1, 2005, 15:17
Default Gravity, UDF Source & Operating Density. HELP ME!
Posts: n/a
I am doing a simple 2-D sway of a rectangular box with air/water. Translation is in the x-direction and gravity acts in the -y direction. I can use my UDF for the x-momentum equation for the sway motion and specify none for the y-momentum equation. Then I turn on gravity as -9.81 in the y-direction and then I specify the operating density as the lighter phase. I run the code and get results.

If my thinking is correct I can do this another way. I can add in gravity as a UDF for the y-momentum equation instead? I made a source term for the y-momentum that is essentially rho*g. When I do this, I now specify gravity as 0 in the Operating Conditions panel for the y-direction and I still set my operating density to the lighter phase. However, my results come out slightly different. I figured they would be the same but they're not. Any suggestions?
  Reply With Quote


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
UDF source term jerome_ FLUENT 2 July 11, 2011 11:55
[Gmsh] Compiling gmshFoam with OpenFOAM-1.5 BlGene OpenFOAM Meshing & Mesh Conversion 10 August 6, 2009 04:26
buyoancy and operating density Zeh FLUENT 2 March 24, 2007 07:22
Please help me run UDF code for source Suga FLUENT 1 February 3, 2006 03:40
Warning 097- AB Siemens 6 November 15, 2004 04:41

All times are GMT -4. The time now is 13:23.