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-   -   How to define porous medium in stardesign? (http://www.cfd-online.com/Forums/cd-adapco/55277-how-define-porous-medium-stardesign.html)

echo April 5, 2006 22:12

How to define porous medium in stardesign?
 
Hi,everyone.I have set up a geometry model in stardesign and plan to define the porous medium.But i don't know how to do this? I can't find any reference about stardesign except the help in the starcd and it doesn't mention this. When i unit all the bodies together, the subdomain type-porous will not be added to a seperate body. But when i don't unit all bodies and define the porous in advance, I can't generate mesh. Does the porous medium need the internal surface as in the prostar? How should i do? I really can't find any reference. help me please! Thanks in advance!

Jamie April 6, 2006 08:35

Re: How to define porous medium in stardesign?
 
If your porous media section does not meet other bodies "face to face" then you will have to use the imprint feature to create common faces between the bodies. Check the STAR-Design help for more information on this feature.

echo April 6, 2006 21:23

Re: How to define porous medium in stardesign?
 
I know the imprint feature and read all the contents about this in the help.I try as possible as my best. But I really can't do this rightly. Let me discribe my model and wish someone will help me. There are four cylinders and two lofts from circle in my medel.The cylinders' coordinate,radius and height are (0,0,0,) r=72 h=150 ,(0,0,150) r=75 h=240 ,(0,0,445) r=20 h=300 ,(0,0,-130) r=20 h=-125 ,and the four circles is (0,0,0) r=75 (0,0,-130) r=20 , (0,0,390) r=75 ,(0,0,445) r=20 .The four circle form two lofts. Now i have difined the inlet,outlet and porous. How should i do to unite and imprint the bodies? thanks a lot!

Malc April 7, 2006 10:16

Re: How to define porous medium in stardesign?
 
If you have performed the imprinting operations correctly, it will not be necessary to unite any of the bodies, and you can assign a porous subdomain to one of the bodies. Obviously all bodies must belong to the same Fluid Domain. I have built your model according to the description and I can mesh this correctly.

Imprinting is described in the manual, Chapter 2, rules for multi-body models.

The cylinder with radius 75 must be imprinted onto the cylinder with radius 72. To do this, first select the cylinder with radius 75, hold down the shift key, and select the cylinder with radius 72. Then click the "Imprint" button. The first body you select is the one that will receive the imprint; the second body you select is used to create the imprint. So in this case we want the imprint of the smaller radius on the cylinder with larger radius.

If the loft created from the first two circles is correct, then you will need to imprint the first (72 radius) cylinder onto this lofted body. To do this, first selected the lofted body, hold down shift key, and select the second body (the 72 radius cylinder). Click Imprint again.

Note that if you want to create a loft between two cylinders, then you can use the "copy" function to copy the face at the end of each cylinder. This is the method described in Tutorial 1.

To mesh this successfully you will probably need to set the relative mesh size to something like 3 %.

Note that the latest version of STAR-Design for STAR-CD is provided as part of the pro-STAR 3.26.006 patch, which you can download from the user services site. If you have the STAR-CCM+/Design Box Set, there is an update for the STAR-Design that goes with that, also available from User Services (STAR-Design version 4.02.32).


echo April 7, 2006 20:28

Re: How to define porous medium in stardesign?
 
Thank you so much! I have done this just as you tell. And it success.Thank you!

ONGODIEBI, ZUONAKI April 25, 2006 07:53

Re: How to define porous medium in stardesign?
 
I need the definition of porous medium both in the medical profession and in applied sciences


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