Restarting a CFX simulation from last stop
 

Hi,

I am running a transient simulation in ANSYS CFX with a total time of 15 secs and a time step of 0.001 sec. But the wall clock time allowed in my university cluster is 24 hours after which I have to start the simulation from the point where it stopped. I am new to doing transient simulations and do not know
much as to how to do this. Can any one explain me how to do this?

Thanks in advance.

P.S: I searched this forum for a similar thread, but could not find one. I apologise if the same problem is already present in this forum.

Regards,
Karthick

I don't have cfx open infront of me so I'm trying to remember by memory.


If you want to restart from the last timestep and simulation time then:
- in cfx transient settings leave initial time set to automatic
- remove any global initialisation parameters you have set
- go to the solver and before you run the simulation give the .res file from the previous run as the initial coconditions, and make sure you keep the "continue history" check box on.

That should work.

To add to Ricochet's comment, you can use both "res" and "trn" files to resume your solution.

OJ

Another thing to consider - you can use the cfx5stop command to stop a run in progress. It will shut down the slover and write a complete results file of whereever it got to. If you want to be clever you can set up a timed job (maybe using cron) to execute cfx5stop just before your time is up. Make sure you give it enough time to complete the timestep it is working on and write the results file.

And to add to Glenn's comment there is no need for cfx5stop (and cron) if you use the 'Elapsed Wall Clock Time Control/Maximum Run Time' in Solver Control.
However I've found that it can be a bit unreliable if you are using many CPU cores (>100).

- The first version was released in what year CFX
- What programming language CFX
- What is an advection
- What are the discretization schemes proposed by CFX

shame on you for breaking almost every forum rule.
http://www.cfd-online.com/Forums/cfx...ease-read.html
http://www.cfd-online.com/Forums/cfx/announcements.html
Have you even opened the manual?

Hi Ricochet,

what is the problem related to the initialisation parameters? Performing a restart the initialisation should be bypassed, right?

I think when you restart the simulation the default option is to initialize from the current results. If you want to initialize from any other results file, then specify its path. But if it is a completely new run that you are after, then just go to Workbench and "reset" the solution tab. Then the initialization will happen from boundaries, that is, fresh run.

I was referring to the standalone version of CFX, sorry if I did not mention it.