# user field function

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

 May 12, 2010, 11:51 user field function #1 New Member   Girish Gaikwad Join Date: Apr 2010 Posts: 11 Rep Power: 9 I want to define new variable {(velocity:Ycomponent)/(free_stream_velocity)}. But in system defined field functions I am not able to find function called velocity:Ycomponent. It is only showing velocity which is a vector quantity. How can I make all components of velocity visible in field functions tab? Please help me. I searched on help menu and got this: System field functions are predefined field functions that are created by the models activated in the continua, and share a particular set of properties. How can I activate velocity components and magnitude?

 May 12, 2010, 14:15 #2 New Member   Pete Launie Join Date: Feb 2010 Posts: 10 Rep Power: 9 Velocity vector components are: \$\$velocity[1] \$\$velocity[2] <--velocity:Ycomponent \$\$velocity[3]

 May 12, 2010, 17:41 #3 New Member   Girish Gaikwad Join Date: Apr 2010 Posts: 11 Rep Power: 9 Thanks a lot. But what is the syntax(definition) for free stream velocity that can be used in the above formula? And also it doesn't show the three components of velocity in field function tab (one of the example in help window showed velocity as well as its three components).

May 12, 2010, 20:24
#4
New Member

Pete Launie
Join Date: Feb 2010
Posts: 10
Rep Power: 9
Quote:
 Originally Posted by girishg Thanks a lot. But what is the syntax(definition) for free stream velocity that can be used in the above formula? And also it doesn't show the three components of velocity in field function tab (one of the example in help window showed velocity as well as its three components).

Question: are you trying to get the velocity magnitude, or velocity at a freestream boundary?

for local velocity magnitude:

I don't know off the top of my head, but Velocity is a vector so...
sqrt(\$\$velocity[1]^2+\$\$velocity[2]^2+\$\$velocity[3]^2) if nothing else.

I think there is a velocity magnitutde field function something like \$velocity.magnitude, or mag(\$\$velocity). I'm not sure I don't have access to the documentation at the moment.

For boundary velocity it's probably just easier to enter the velocity. i.e.

\$\$velocity[2]/12345

 May 12, 2010, 21:32 #5 Member   Vinicius Girardi Join Date: Mar 2009 Location: Sao Paulo, Brazil Posts: 80 Rep Power: 10 for velocity magnitude, use mag(\$\$Velocity) and for Y direction, use \$\$Velocity[1]. The directions X,Y,Z are represented by [0],[1],[2] respectively.

 May 13, 2010, 09:21 #6 New Member   Girish Gaikwad Join Date: Apr 2010 Posts: 11 Rep Power: 9 Thanks a lot guys!!!

 Tags field function

 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 Subhadeep STAR-CCM+ 8 February 18, 2010 18:19 hannow STAR-CCM+ 3 November 24, 2009 21:20 Cagdas FLUENT 1 September 5, 2007 20:02 Christian Main CFD Forum 2 February 27, 2007 07:27 greg FLUENT 2 May 23, 2006 10:42

All times are GMT -4. The time now is 17:47.