CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Create a time related function

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 28, 2005, 09:51
Default Create a time related function
  #1
Eric
Guest
 
Posts: n/a
As we knew fluent using steady flow for all the cases. but in some cases, if we wanted to create a unsteady mass flow for the stimulation. what can we do? simply to say, let me simply the problem of inlet mass flow rate be 30sin(pi * t)+ 90. then how can we change the way of steady flow to such unsteady flow.

was it done by creating a user defined function? or something else? please help me
  Reply With Quote

Old   March 2, 2005, 06:06
Default Re: Create a time related function
  #2
Melaku H.
Guest
 
Posts: n/a
Hi,

I don't know your particular problem but in general it is possible to write a simple UDF code to do just that!

Melaku H.
  Reply With Quote

Old   March 3, 2005, 09:03
Default Re: Create a time related function
  #3
peter
Guest
 
Posts: n/a
A very closely related example (transient velocity profile) is given in section 11.1 of the FLuent 6.1 UDF manual)
  Reply With Quote

Old   March 3, 2005, 13:30
Default Re: Create a time related function
  #4
Eric
Guest
 
Posts: n/a
OK, i try to use this . Besides, how can i change it similarly so that a UDF of preesure can be constructed?

thanks For peter
  Reply With Quote

Old   March 4, 2005, 11:58
Default Re: Create a time related function
  #5
Eric
Guest
 
Posts: n/a
but as i think more carefully, the UDF in the section 11.1 only give a varying flow pattern along different distance. this is not the problem i wanted to solve. what i need is the way which the flow of the whole region with a mass flow rate vary with respect of time. As the way of 11.1 only provided the minimum velocity in the middle of region.

so i think this is not the same case. what can i do ???

thanks in advance
  Reply With Quote

Old   March 14, 2005, 15:53
Default Re: Create a time related function
  #6
matt
Guest
 
Posts: n/a
Hi Eric,

If you want to vary the inlet boundary condition with respect to time how about trying the DEFINE_PROFILE macro - something like of Example 1 in Section 4.3.13, UDF Manual with time being the variable in the function.

Declare time as a variable and then as equal to the value of a time dependent macro as in Section 6.7

good luck,

matt.
  Reply With Quote

Reply

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
Moving mesh Niklas Wikstrom (Wikstrom) OpenFOAM Running, Solving & CFD 122 June 15, 2014 07:20
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 05:03
Where's the singularity/mesh flaw? audrich FLUENT 3 August 4, 2009 02:07
Convergence moving mesh lr103476 OpenFOAM Running, Solving & CFD 30 November 19, 2007 15:09
DecomposePar links against liblamso0 with OpenMPI jens_klostermann OpenFOAM Bugs 11 June 28, 2007 18:51


All times are GMT -4. The time now is 18:25.