CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   how to specify inlet conditions from prev case? (http://www.cfd-online.com/Forums/fluent/32053-how-specify-inlet-conditions-prev-case.html)

chanchala August 29, 2003 08:44

how to specify inlet conditions from prev case?
 
Hi everyone,

I've solved a case that consists of turbulent flow through 2 pipes. I want to add on another pipe at the exit of these 2 pipes and solve for the end pipe. I need to repeat for many end pipes so it would be easier for me to use data from prev. case and solve only for end pipe.

Is it possible for me to specify the velocity data at the exit of the solved case as entry conditions for the end pipe? I tried simply taking average velocities (axial, radial and tangential) and putting these in inlet BC but the distribution is the not the same as it is at the exit of prev. case. Is there a way to copy the exit distribution exactly?

ap August 29, 2003 12:25

Re: how to specify inlet conditions from prev case
 
You can export profiles from your old case and import them in your new case file.

To export a profile: Define->Profiles->Write...

Choose the BC you want and the variables you want to export. Then click on write.

To import a profile: Define->Profiles->Read.

Hi

ap

chanchala August 29, 2003 13:25

Re: how to specify inlet conditions from prev case
 
Hi ap,

I tried as you said. Imported the profile files into my case and defined the inlet BC using the cylindrical velocity profiles (from drop down menu). When I initialise and look at the contour for the inlet it's just red, green and yellow (each a 1/3rd) and not my profile from before. What's gone wrong? Thanks for your help!

chanchi

ap August 29, 2003 14:14

Re: how to specify inlet conditions from prev case
 
Try doing one iteration and check again. I think FLUENT applies BC profiles at the first iteration, not when you define them or initialize variables.

To do a better check, do an XY plot selecting your inlet, instead of checking contours. This way FLUENT will show you the profile.

Keep me up to date

Hi :=)

ap

chanchala September 1, 2003 11:59

Re: how to specify inlet conditions from prev case
 
Hi ap,

thanks very much for that. Its fine once I've done a few iterations. I did think that I should've done a few iterations before checking but only once I got home!

D'you mind my asking what you use Fluent for? I've got a lot of help from people on this forum. I myself am a research PhD student.

cheers, Chanchi

ap September 1, 2003 16:59

Re: how to specify inlet conditions from prev case
 
I'm using FLUENT to simulate gas-solid flows in a riser of a circulating fluidized bed reactor .

The final purpose is to simulate the whole loop of the CFBR system.

If you want more information, please post here or e-mail.

Hi :)

ap


All times are GMT -4. The time now is 22:34.