CFD Online Discussion Forums

CFD Online Discussion Forums (
-   CFX (
-   -   Transient Results (

Ogbeni November 26, 2004 12:00

Transient Results
Hello All, I need some explanation on obtaining transient results fron CFX5. I had completed a transient simulation and tried to export it to fieldview, but to my astonishment only the last state was present. Should I have requested a minimal result at some time interval with defined variables ? or full ? I will appreciate if some one can help to understand how to obtain a comprehensive result over the entire time period.

jon November 26, 2004 13:22

Re: Transient Results
You need to specify Transient results in Output Options. You can choose timesetep list or interval.

You can choose minimal or full results.

You can have a mixture of either the above options.

Rui November 26, 2004 13:34

Re: Transient Results

In CFX-Pre, Output Control, you have to create Transient Results (as many as you want). You may chose the option minimal and define the variables you want, or the option full. You may also chose between the options time interval (the results files will be created at every interval) or time list ( the results files will be created at each time instant of the list).

I use to create transient results: 1- with the most important variables, with a small time interval; 2- with the option full, with a larger time interval; and 3- with the option full at some time instants I consider important.

If your simulations take a long time to complete, it is also advisable to create backup results with the option full, so you may restart your simulation at the last backup, if for some reason your computer crashes or the power shuts down.

At the manual you will find further information about the Output Control possibilities. Also, take a look at the tutorials with transient simulations.



Roe November 30, 2004 07:09

Re: Transient Results
CFX will NOT export minimal transient result files to FV. You must use the 'full' option in 'Transient Results'

Ogbeni November 30, 2004 08:10

Re: Transient Results
Hello Roe, Does tha mean I must indicate several time steps under the full option ? it seems that the full option gives only the last tine step.

Roe November 30, 2004 10:43

Re: Transient Results
'Fraid so. Say your solution timestep is 1e-3 seconds, to get a result file every 10 timesteps you must set your 'Time Interval' on the 'Transient Results' tab to be 1e-2 seconds. Alternatively you can specify exact times to write a transient result file under the 'Time List' option. These files will appear as *.trn in the run time directory (*.dir). For the export to FV to work correctly, you must have the 'Full' option selected. You don't need to output boundary flows or equation residuals.

All times are GMT -4. The time now is 11:53.