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-   -   Boundary Condition/Profiles (http://www.cfd-online.com/Forums/fluent/29638-boundary-condition-profiles.html)

Alex April 15, 2002 10:35

Boundary Condition/Profiles
 
Hi all,

I'm using a profile to define the boundary condition at outlet. Does anyone know at what point I can visualise the condition? Do I have to do some iterations before I can plot the countour for my outlet? Problem being, I do not visualise any of my condition while same procedure at inlet give perfect results....spooky.

Many thanks,

Alex

chiseung April 16, 2002 07:57

Re: Boundary Condition/Profiles
 
After reading the profile file, iterate just one time and use "XY Plot" in solver.

Alex April 17, 2002 07:38

hmm not working...
 
Hy Chiseung,

thanks for the hint. Unfortunatly it doesnt work in my case and whatever I do, the outlet can be but uniform(or at least not what I want it to look like).

Inlet is ok(but already was). Plus, I am working in 3D which means that I'd better use DISPLAY/CONTOUR> at outlet(easier to visualie the flow field).

Could it be related to initialisation(because I'm not doing any since I am startinf from an already converged solution with uniform boundary condition).

Help still welcomed,

Alex

chiseung April 17, 2002 22:37

Re: hmm not working...
 
First, have you changed the option in boundary condition? Just reading the profile file is meaningless.

I tested a simple 3d cylindrical type duct problem but there was no problem in setting b.c. However, I guess, you want to fix your outflow boundary values using solved value. In this case, you can't change your boundary conditon because there is no drop down list in outflow boundary condition panel. So, I think, changing outflow boundary to another proper b.c. could be one solution or using user defined function could be another solution.

P.S. The function of "profile" file is to change your boundary values you want. So, as far as I know, initialization doesn't affect your bounday values.

Peter April 18, 2002 15:00

Re: Boundary Condition/Profiles
 
Alex,

Since you are prescribing a boundary condition, you just need to iterate once and then the you should get the value that you prescribe on the boundary as a result. Be aware, that FLUENT uses cell values to specify the domains. When you visualize you results, Are you lloking at node or cell values?. That's make a difference. Another thing, I would prefer to check ot with a XY plot rather than a contour plot.

Cheers

Alex May 3, 2002 05:23

Good news
 
Hi all,

describe below is a valid procedure to: 1) use time dependent profile created by extraction of experimental data(no UDF) 2) visualise the profile rotation

#1
:create a my_profile.prof containing all the requiered info ((my_pro point 1) (x 1) (y 1) (z 1) (my_var_t=0 1) (my_var_t=1 2) (my_var_t=2 3) )
:read the profile and set my_bound_cond with my_var_t=0
:initialise from the zone linked to my_bound_cond(or all_zone)
:write initial data label_1
:set my_bound_cond as my_var_t=1
:get convergence with unsteady
:write data_t=1.dat ...repeat process from label_1

#2 To be sure that the condition at outlet were 1) matching what I wanted them to match 2) rotating,

I used TECPLOT. With the my_profile.prof I created a profile.dat which I imported in TECPLOT and extrapolated on a my_grid.plt (exported from FLUENT). Then I got all the 1,2,3 time dependent condition for _my_boundary. After each setting of my_bound_cond as my_var_t=* I export a TECPLOT file. Then having gather the 2 different sets of data(original and FLUENT) I create 2 .avi files and I visualise them.

Many thanks to all those who contributed to help me on that one!!

Alex


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