CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   CFX (https://www.cfd-online.com/Forums/cfx/)
-   -   Is it possible to import boundary conditions? (https://www.cfd-online.com/Forums/cfx/25655-possible-import-boundary-conditions.html)

Tim April 15, 2008 01:29

Is it possible to import boundary conditions?
 
Hi,

I have run a simulation successfully that gives results. If I have a new simulation that has one surface having the same geometry as the old simulation, can I use the results for the surface of the old simulation as inlet boundary conditions for the new simulation? If this is possible how can it be done?

Also, if the old simulation was transient over 1 second, can I import the inlet boundary conditions as a function of time and run the new simulation over the same time period (1 second)?

Thanks, Tim.

Tim April 15, 2008 01:29

Re: Is it possible to import boundary conditions? *NM*
 

andy2O April 15, 2008 13:34

Re: Is it possible to import boundary conditions?
 
OK, here's an answer which I know works for steady states. You are obviously also interested in transients, and unfortunately I cannot help you with that. But perhaps my answer will provide some clues / some help to you... and hopefully someone else will answer about time-dependence.

For a steady-state you need "Profile boundary data". Look this up in the CFX help (you might need a slightly different seach term - but I'm sure you'll find it). Basically, you need to:

1) Choose 'Export' from the file menu in CFX-Post and export a 'BC Profile' containing the data you need on the surfaces of interest.

2) Now go to CFX-Pre. Choose 'Initialise Profile Data' from the "Tools" menu in CFX-Pre.

3) Now edit your boundary condition, and there will be an option to 'Use profile data'. Select this. Then click on 'Generate values'.

4) You can also plot contours in CFX-Pre showing the profile boundary condition values to confirm it has worked. To do this edit the boundary condition and go to the righthand tab and select the appropriate box / boxes.

I've just used this method myself this-afternoon. It works well for steady states. I cannot answer your second question about transients. I hope someone else will.... There may be other ways of exporting the data that are more convenient for a transient run.

Good luck, Andy

Tim April 15, 2008 18:03

Re: Is it possible to import boundary conditions?
 
Hi Andy,

Thanks for your help, I will definately give that a try first thing this morning.

Tim April 16, 2008 00:54

Re: Is it possible to import boundary conditions?
 
Hi,

Thanks again for your help, I have successfully implemented the procedure you have described. I would also like to do this process for a multiphase simulation, however it doesn't seem to like me doing this. I would like to import the mass flow rate of the continuous phase and the solid dispersed phase, and also the volume fraction of each. I think it just requires stuffing around with field names, but I cant seem to get it right.

Tim.


All times are GMT -4. The time now is 11:35.