CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Read boundary conditions from previously computed time steps or from file?

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 14, 2013, 04:57
Default Read boundary conditions from previously computed time steps or from file?
  #1
New Member
 
Join Date: Oct 2012
Posts: 17
Rep Power: 14
cuba is on a distinguished road
Hi everyone,

I am using a modified version of pimpleDymFoam in OF-1.6-ext.

To explain the problem briefly, as an example,

from 0 to 2 seconds, I wait for the flow condition to reach its steady state, later,
for the next 10 seconds (from 2 - 12)
I want to make sure that the program reads the boundary conditions at the inlet for the velocity and some other parameters
from the folder created at the end of 2nd sec time step, where I assume that it has reached its steady state.

How can I define my boundary conditions at the inlet to be read from a file or a folder which is previously computed?

Thanks again in advance for your valuable comments and replies
Best
cuba is offline   Reply With Quote

Old   February 14, 2013, 06:34
Default
  #2
Member
 
sushant's Avatar
 
Join Date: Mar 2009
Location: Switzerland
Posts: 40
Rep Power: 17
sushant is on a distinguished road
Quote:
Originally Posted by cuba View Post
Hi everyone,

I am using a modified version of pimpleDymFoam in OF-1.6-ext.

To explain the problem briefly, as an example,

from 0 to 2 seconds, I wait for the flow condition to reach its steady state, later,
for the next 10 seconds (from 2 - 12)
I want to make sure that the program reads the boundary conditions at the inlet for the velocity and some other parameters
from the folder created at the end of 2nd sec time step, where I assume that it has reached its steady state.

How can I define my boundary conditions at the inlet to be read from a file or a folder which is previously computed?

Thanks again in advance for your valuable comments and replies
Best
Stop your simulation after 2 seconds, copy the files from 2/* to 0/* (backup your 0 folder if you want to; then overwrite it). Open the files that are now in 0/ and (scroll down a lot) change the velocity / other parameters at the desired boundaries to fixedValue from whatever they were before. The value will be a large nonuniform table, leave it untouched. Change the run time in controlDict and continue the run. I assume of course that the writeFormat in controlDict is ascii from the beginning of the run.

Or are you looking to automate this? PyFoam has a utility that will do the copying part elegantly for you.

If the mesh has changed between 0-2s, and you get errors while continuing, you may also need to copy from 2/polyMesh/* into constant/polyMesh (backup the original).
sushant is offline   Reply With Quote

Old   February 14, 2013, 08:48
Default
  #3
New Member
 
Join Date: Oct 2012
Posts: 17
Rep Power: 14
cuba is on a distinguished road
Thanks for such a quick reply.. a very good idea indeed

then my second question is

how to output the values of some of the parameters at the inlet, which are defined as zeroGradient at 0th time.

because even for the 2nd time step, at the inlet, when I look at the boundaryField, I see the respective boundary condition defined as in 0, but not like a table with the values.

Thanks again
cuba is offline   Reply With Quote

Reply


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
Wind turbine simulation Saturn CFX 60 July 17, 2024 06:45
AMI speed performance danny123 OpenFOAM 21 October 24, 2020 05:13
[swak4Foam] Error bulding swak4Foam sfigato OpenFOAM Community Contributions 18 August 22, 2013 13:41
friction forces icoFoam ofslcm OpenFOAM 3 April 7, 2012 11:57
Could anybody help me see this error and give help liugx212 OpenFOAM Running, Solving & CFD 3 January 4, 2006 19:07


All times are GMT -4. The time now is 21:22.