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

time independence study

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   December 2, 2022, 04:07
Default time independence study
  #1
Member
 
naji
Join Date: Nov 2022
Posts: 37
Rep Power: 3
aiden_1995 is on a distinguished road
Hi guys
I'm doing a time independence study
i have 4 time steps and i did the simulation and defined a report definition for the parameter but after ending the simulation i realized that reports weren't saved,is there any other way to compare the results except plotting based on time for time study? i have no data to compare(except case and data of every simulation) and solution time is a lot
if anyone has an idea i would appreciate
aiden_1995 is offline   Reply With Quote

Old   March 7, 2023, 04:15
Default
  #2
New Member
 
Nilotpal Dhar
Join Date: Nov 2022
Location: United Kingdom
Posts: 4
Rep Power: 3
ndhar is on a distinguished road
How are you defining the parameter? In the controlDict as functions?
ndhar is offline   Reply With Quote

Old   March 7, 2023, 12:52
Default
  #3
Senior Member
 
CFDKareem's Avatar
 
Kareem
Join Date: Nov 2022
Location: New York
Posts: 120
Rep Power: 3
CFDKareem is on a distinguished road
Quote:
Originally Posted by aiden_1995 View Post
Hi guys
I'm doing a time independence study
i have 4 time steps and i did the simulation and defined a report definition for the parameter but after ending the simulation i realized that reports weren't saved,is there any other way to compare the results except plotting based on time for time study? i have no data to compare(except case and data of every simulation) and solution time is a lot
if anyone has an idea i would appreciate
It depends on the simulation you are preforming. If the setup is steady state, or transient but approaching steady state, you can compare final numbers from each case.

For example, assuming you are looking at an airfoil and your chosen parameter is the drag coefficient. You can determine the ending coefficient from each simulation and compare them against each other. By comparison I mean looking at the relative percent change between each mesh. Once the change is below 1%-5% (depending on you simulation, tolerance, etc.) you should be independent.

If, however, the simulation is transient (moving wall, changing boundary condition, etc.) your critical parameter will likely not be a single number, but a transient plot or profile. In this case there's unfortunately no way to recover the transient data if you did not export it.

If you can provide more detail on your problem I can help you determine an adequate parameter to investigate.
__________________
Please like the answer if it helped!

Video Tutorials and Tips: https://www.youtube.com/@cfdkareem/featured
CFDKareem is offline   Reply With Quote

Reply

Tags
time study, transient


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
bash script for pseudo-parallel usage of reconstructPar kwardle OpenFOAM Post-Processing 42 May 7, 2024 23:17
pressure in incompressible solvers e.g. simpleFoam chrizzl OpenFOAM Running, Solving & CFD 13 March 28, 2017 05:49
Floating point exception error lpz_michele OpenFOAM Running, Solving & CFD 53 October 19, 2015 02:50
Star cd es-ice solver error ernarasimman STAR-CD 2 September 12, 2014 00:01
plot over time fferroni OpenFOAM Post-Processing 7 June 8, 2012 07:56


All times are GMT -4. The time now is 21:59.