CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > CFX

Timestep-Control (Subroutine)

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 9, 2005, 12:02
Default Timestep-Control (Subroutine)
  #1
Gabor
Guest
 
Posts: n/a
Hi,

I have a problem with timestep control in user-fortran Subroutines! My task is to write a subroutine for the fluid-structure-interaction (FSI) without using the given MPCCI code.

Now I planned to write a routine, which is called at the end of each timestep and check the convergence of the calculated solution. If the convergence is OK, the simulation keeps on going and the next timestep is calculated.

But if the convergence is bad, the solver should jump to the end of the timestep before and repeat calculating the actual timestep.

Therefore I will have to manipulate the solver-stack and I need more informations about the solver data-structure!

So here are my questions to specialists in CFX:

1. Where can I find detailed informations about the solver data-structure?

2. Which data has to be manipulated, to set the solver to the end of a before calculated timestep? (f.e. copy /FLOW/SOLUTION/LATEST to /FLOW/SOLUTION/TSTEPn/CLOOPm, or setting ATSTEP to a special value)

Thanks for any reply,

Gabor

  Reply With Quote

Old   November 14, 2005, 02:22
Default Re: Timestep-Control (Subroutine)
  #2
Jeff
Guest
 
Posts: n/a
The only MMS information available is in the CFX Solver Modeling manual under User Fortran.

I wouldn't hold my breath about backing up a time step without a LOT of help from ANSYS. There is an adaptive time stepping example in the above mentioned manual, but it only cuts the time step if the current step uses more than a recommended number of coefficient loops, then proceeds on to the next step. This has worked pretty well for me without needing to go back and re-run a timestep. I'd try this first.

I think this is also implemented in CFX-10 without using the additional Fortran.

Jeff
  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Problems of running Oscillating plate tutorial vovogoal CFX 17 December 30, 2014 05:00
Problems with adjustable timestep control and maxCo Number wolle1982 OpenFOAM Running, Solving & CFD 4 July 27, 2011 05:40
error in two way fsi kmgraju CFX 1 May 2, 2011 02:32
Timestep control via CEL? Claudia CFX 7 September 14, 2007 05:00
GETVAR SUBROUTINE for additional variable in CFX Tuks Main CFD Forum 0 November 8, 2005 07:13


All times are GMT -4. The time now is 07:57.