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

visualising time derivatives

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   November 9, 2012, 00:14
Default visualising time derivatives
  #1
New Member
 
Join Date: Mar 2010
Posts: 25
Rep Power: 16
Dorit is on a distinguished road
Hi everyone,

I hope that someone has a simple suggestions for what I'm trying to do. I basically want to plot the time derivative of for instance the x velocity in an unsteady simulation. I then want to export the x acceleration contour every N time steps.

Solution 1) Somehow create a new variable that calculates the x acceleration at every time step and then use the automatic export feature. I don't think this can be done using the Custom Field Function Calculator. Any ideas?

Solution 2) Write a UDF that calculates the x acceleration and writes it to an output file. I've found out about the C_U(c,t) and C_U_M1(c,t) functions which give me the x velocity from the current and previous time step, so it's easy to get the acceleration. But I'm having trouble with using thread_loop_c and begin_c_loop_all macros to access all cells/nodes on the surface of interested. Aside from that I wouldn't know how to save it in a format which allows the data to be easily visualised in Tecplot again.

Thanks for any thoughts/comments.
Dorit
Dorit is offline   Reply With Quote

Reply

Tags
acceleration, contour, post procesing, time derivative, udf exporting variable


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
InterFoam negative alpha karasa03 OpenFOAM 7 December 12, 2013 04:41
pisoFoam with k-epsilon turb blows up - Some questions Heroic OpenFOAM Running, Solving & CFD 26 December 17, 2012 04:34
Upgraded from Karmic Koala 9.10 to Lucid Lynx10.04.3 bookie56 OpenFOAM Installation 8 August 13, 2011 05:03
directMapped problem panda60 OpenFOAM Bugs 4 July 8, 2010 11:23
Computational time sunnysun OpenFOAM Running, Solving & CFD 5 March 16, 2009 04:32


All times are GMT -4. The time now is 08:43.